Researcher Profile and Settings

Master

Affiliation (Master)

• Faculty of Engineering　Mechanical and Aerospace Engineering　Aerospace Systems

Affiliation (Master)

• Faculty of Engineering　Mechanical and Aerospace Engineering　Aerospace Systems

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Profile and Settings

Degree

• Ph.D. in engineering（Kyushu University）

Profile and Settings

• Name (Japanese)

  Takahashi

• Name (Kana)

  Yusuke

• Name

  201301029087204951

Alternate Names

http://kaken.nii.ac.jp/d/r/40611132.ja.html

Achievement

Research Interests

• Arc-heated wind tunnel   Reentry vehicle   High enthalpy flow   

Research Areas

• Aerospace, marine, and maritime Engineering / Aerospace engineering

Research Experience

• 2021/04 - Today Hokkaido University Faculty of Engineering Associate Professor
• 2012/04 - 2021/03 Hokkaido University Faculty of Engineering Assistant Professor
• 2016/04 - 2017/03 German Aerospace Center (DLR) Supersonic and Hypersonic Technologies Department of the Institute of Aerodynamics and Flow Technology Visiting Researcher
• 2011/04 - 2012/03 Japan Aerospace Exploration Agency

Awards

• 2023/04 Hokkaido University Distinguished Researcher
   

  受賞者: 高橋裕介
• 2021/03 北海道大学大学院工学研究院 若手教員奨励賞
   

  受賞者: 高橋裕介
• 2020/04 文部科学省 令和２年度科学技術分野の文部科学大臣表彰 若手科学者賞
   大気再突入宇宙機の高速気流 とマルチフィジクスの研究 

  受賞者: 高橋裕介
• 2018/04 The Japan Society of Mechanical Engineers JSME Young Engineers Award
   数値流体・電磁場解析による宇宙機の再突入ブラックアウト予測の研究 

  受賞者: Yusuke Takahashi
• 2018/03 日本機械学会宇宙工学部門 宇宙賞
   

  受賞者: 展開型エアロシェル実験超小型衛星(EGG) チーム
• 2016/10 HPCI利用研究課題成果報告会 平成27年度実施課題における「京」を含むHPCI利用研究課題優秀成果賞
   「惑星大気再突入機に対する通信ブラックアウト評価ツールの構築」 

  受賞者: 高橋裕介
• 2016/02 一般財団法人コージェネレーションエネルギー高度利用センター 平成27年度コージェネ大賞 技術開発部門特別賞
   

  受賞者: 川崎重工業株式会社;北海道大学

Published Papers

• Spatiotemporal mode extraction for fluid–structure interaction using mode decomposition

  Yusuke Takahashi

  Journal of Sound and Vibration 118804 - 118804 0022-460X 2024/11 [Refereed][Not invited]
  
• Mode decomposition to identify oscillation patterns of flexible aeroshell

  Sanjoy Kumar Saha, Yusuke Takahashi

  Physics of Fluids 36 (11) 1070-6631 2024/11/01 [Refereed][Not invited]
   

  Flexible aeroshells, featuring deformable membrane surfaces supported by pressurized gas, offer a novel re-entry system for high-altitude deceleration during re-entry. The flexibility of structural components introduces unique challenges in predicting aerodynamic behavior, as deformations can significantly alter the flow field, affecting pressure distribution and potentially causing aerodynamic instabilities. Therefore, coupled analysis is crucial to ensure the performance reliability of inflatable aeroshells. This study investigates the unsteady aerodynamic behavior, considering structural deformation in a two-way partitioned coupled manner in transonic flow. The dominant deformation patterns are identified using dynamic mode decomposition and the greedy compressive sensing algorithm. The findings reveal that the primary deformation pattern combines axial deformation and swing oscillation. The dominant oscillation frequencies remain different from the eigenfrequencies, indicating that the aerodynamic force is the primary driving force of such oscillations. The time evolution of these dominant modes indicates purely oscillatory behavior rather than increasing or decreasing trends. These insights are critical for the design and reliability assessment of inflatable aeroshells in varying aerodynamic environments.
• Aerostructural Analysis of a Deployable Aeroshell in Transonic Flow

  Sanjoy Kumar Saha, Yusuke Takahashi

  AIAA Journal 1 - 16 0001-1452 2024/10/07 [Refereed][Not invited]
   

  The deployable aeroshell, a contemporary reentry system, utilizes a thin flexible membrane surface sustained by pressurized gas to efficiently decelerate a reentry vehicle at high altitudes while enabling low-ballistic-coefficient flight. When an in-flight aerodynamic force is applied, the membrane structure undergoes large deformation that may affect its performance. Hence, a coupled analysis that considers the feedback effect of structural deformation is essential for accurately predicting the behavior of such reentry vehicles. In this study, a numerical framework for coupled aeroelastic analysis was constructed in a partitioned manner using open-source software to elucidate the combined effect of structural deformation and compressible flow dynamics and characterize the aerodynamic performance of reentry vehicles with inflatable structures. The results revealed that the membrane surface was deformed elastically by the aerodynamic force owing to the large difference in pressure distribution between the front and back of the aeroshell. Fluctuating behavior was observed in the aerodynamic coefficients owing to the small-amplitude oscillation of the capsule. This oscillation was induced by the large wake behind the vehicle. Several wrinkles and concave-shaped depressions formed on the membrane surface, which exhibited a circumferential movement tendency with time.
• Atmospheric density estimation in very low Earth orbit based on nanosatellite measurement data using machine learning

  Tomoki Sakai, Yusuke Takahashi

  Aerospace Science and Technology 153 109418 - 109418 1270-9638 2024/10 [Refereed][Not invited]
  
• Mitigation of reentry blackout via gas injection in arc-heating facility

  Takashi Miyashita, Yuji Sugihara, Yusuke Takahashi, Yasunori Nagata, Hisashi Kihara

  Journal of Physics D: Applied Physics 57 (32) 325206 - 325206 0022-3727 2024/05/20 [Refereed][Not invited]
   

  Abstract Communication blackouts during atmospheric reentry pose significant challenges to the safety and adaptability of spacecraft missions. This phenomenon, caused by the attenuation of electromagnetic waves by the plasma surrounding the spacecraft, disrupts communication with ground stations or orbiting satellites. Therefore, it is crucial to decrease the plasma density in the vicinity of the spacecraft to ensure an unobstructed electromagnetic wave communication path. This study proposes a methodology that involves the injection of gas from the vehicle’s wall to create an insulating layer near the surface. This thin layer maintains lower temperatures and reduced plasma density, enabling electromagnetic wave propagation without attenuation. Practical experiments were conducted in an arc-heating facility to simulate atmospheric reentry conditions. The results of the experiments provided empirical evidence of the effectiveness of the technique in mitigating communication blackout phenomena. Numerical fluid analysis within the wind tunnel chamber validated the formation of an air film layer near the experimental model owing to the injected gas. Schlieren imaging revealed distinctive jet shapes, which corroborated the findings of the numerical analysis. The wind tunnel tests that simulated atmospheric reentry environments confirmed the formation of an air film layer through gas injection, which substantiates the reduction in communication blackout. These results have the potential to improve communication reliability in space transport.
• Static attitude stability of deep space sample return capsule with thin aeroshell

  Hideto Takasawa, Tomoya Fujii, Yusuke Takahashi, Takahiro Moriyoshi, Hiroki Takayanagi, Yasunori Nagata, Kazuhiko Yamada

  CEAS Space Journal 1868-2502 2024/04/26 [Refereed][Not invited]
  
• Computational Study on Air Film Approach in Reentry Blackout Mitigation

  Takashi Miyashita, Hideto Takasawa, Yusuke Takahashi, Lars Steffens, Ali Gülhan

  AIAA Journal American Institute of Aeronautics and Astronautics (AIAA) 62 (2) 437 - 448 0001-1452 2024/02 [Refereed][Not invited]
   

  Communication blackouts during the atmospheric reentry phase are a significant challenge, as flight data are lost due to interruptions caused by plasma gas generated by aerodynamic heating. This study explores a novel mitigation method using an air film, a thin insulating coolant layer on the surface. The researchers successfully reduced the reentry blackout by employing a gas injection system. Through a coupled approach using computational fluid dynamics and a frequency-dependent finite-difference time-domain method, the plasma flow properties and electromagnetic propagation were analyzed around a test model in a wind tunnel in DLR (German Aerospace Center). The numerical results indicated that the injected nitrogen gas formed an insulating air film layer on the surface. The thin layer advected backward, maintaining a low temperature without ionization, and covered the object in the wake region. The electromagnetic waves propagated and reached a distant area because the electron density was low. It means that the air film layer acted as a propagation window for the telecommunication waves. Thus, communication blackouts will be avoidable because electromagnetic waves can transmit through the air-film layer. It concluded that the air film effect, developed as a thermal protection technique, is a novel mitigation scheme for reentry blackouts.
• Free flight demonstrations for sample return capsules with thin aeroshell using rubber balloons: RERA-2 & RERA-3

  宮下岳士, 高澤秀人, 玉井亮多, 平田耕志郎, 若林海人, 吉雄忠行, 山本春佳, 丹野茉莉枝, 高橋裕介, 永田靖典, 山田和彦

  宇宙航空研究開発機構研究開発報告: 大気球研究報告 JAXA-RR-23-003 59 - 75 2024/02 [Refereed][Not invited]
  
• Dynamic instability modeling on phase plane for thin aeroshell capsule with pitching motion at transonic speed

  Hideto TAKASAWA, Tomoya FUJII, Koshiro HIRATA, Takahiro MORIYOSHI, Yusuke TAKAHASHI, Yasunori NAGATA, Kazuhiko YAMADA

  Mechanical Engineering Journal 11 (3) 24-00053  2024 [Refereed][Not invited]
  
• Numerical investigation of surface catalytic effect on the plasma sheath of a hypersonic re-entry capsule

  Yu Minghao, Qiu Zeyang, Yusuke Takahashi

  Physics of Fluids 35 (5) 1070-6631 2023/05/01 [Refereed]
   

  Radio frequency blackout indicates the communication interruption between signal monitoring sites and re-entry vehicles; it is a serious threat to the safety of astronauts and the space exploration missions. In this study, a surface catalytic model coupled with a thermochemical non-equilibrium computational fluid dynamic model is developed to study the catalytic wall effect on the plasma sheath of a hypersonic re-entry vehicle. The mechanism of the surface catalytic effect on the plasma sheath of a re-entry capsule is revealed by a comparative study. The flow-field characteristics simulated under conditions of the full-catalytic and non-catalytic walls are compared and discussed for the hypersonic atmospheric re-entry capsule at different altitudes. The chemical and physical mechanisms behind the surface catalytic effect of the re-entry capsule are analyzed. The experimental data of Radio Attenuation Measurement-C-II are used to validate the numerical model established in the present study. It is found that the numerical results simulated with the fully catalytic wall are more consistent with the experimental data. Near the capsule wall, the mole fractions of the species N, O, N+, and O+ decrease as the catalytic recombination coefficient increases. Because of the surface catalytic effect, the communication black is mitigated due to the reduction of the electron number density in the wake zone of the capsule.
• RERA: Rubber balloon Experiment for Reentry capsule with thin Aeroshell

  Hideto Takasawa, Yoichi Suenaga, Takahashi Miyashita, Koshiro Hirata, Kaito Wakabayashi, Yusuke Takahashi, Yasunori Nagata, Kazuhiko Yamada

  JAXA Research and Development Report JAXA-RR-22-008 37 - 50 2023/02 [Refereed][Not invited]
  
• Fluid-structure interaction characteristics of inflatable reentry aeroshell at subsonic speed

  Sanjoy Kumar Saha, Junki Tobari, Yusuke Takahashi, Nobuyuki Oshima, Takahiro Moriyoshi, Kazuhiko Yamada, Ryoichi Shibata

  Aerospace Science and Technology 133 108112 - 108112 1270-9638 2023/02 [Refereed]
  
• Numerical simulation of thermochemical non-equilibrium flow-field characteristics around a hypersonic atmospheric reentry vehicle

  Minghao Yu, Zeyang Qiu, Bowen Zhong, Yusuke Takahashi

  Physics of Fluids AIP Publishing 34 (12) 126103 - 126103 1070-6631 2022/12 [Refereed]
   

  A multi-physics thermochemical non-equilibrium model is established to study the flow characteristics of the plasma sheath around an atmospheric reentry demonstrator. This model includes the tight coupling of Navier–Stokes equations, 54 chemical reactions of air, and a four-temperature model. The processes of dissociation, ionization, and the internal energy exchanges of air components were successfully simulated during aerodynamic heating of the reentry vehicle. The distributions of plasma sheath temperature, the molar fraction of air species, stagnation pressure, surface pressure, and electron number density around the reentry vehicle were obtained at different flight altitudes. Additionally, to validate the numerical model developed in this study, the flow characteristics of the Radio Attenuation Measurement-C-II (RAM-C-II) vehicle are also simulated and then compared with corresponding experimental data. They show good consistency in general. It is found that when the vehicle is at a high flight altitude, there is a strong thermochemical non-equilibrium phenomenon around the vehicle. However, the plasma sheath tends to be in local thermal equilibrium at a low flight altitude. The distance from the shock layer to the stagnation point decreases with a decrease in reentry altitude from 90 to 65 km but increases with a decrease from 65 to 40 km. The electron number density in the shock layer is maximum. The distribution of the electron number density in the wake region differs significantly at different flight altitudes.
• Propagation Path of Radio Waves in Nonequilibrium Reentry Plasma Around a Nanosatellite With an Inflatable Aeroshell

  Yusuke Takahashi

  IEEE Transactions on Aerospace and Electronic Systems 58 (5) 4070 - 4082 0018-9251 2022/10 [Refereed]
  
• Trajectory reconstruction for nanosatellite in very low Earth orbit using machine learning

  Yusuke Takahashi, Masahiro Saito, Nobuyuki Oshima, Kazuhiko Yamada

  Acta Astronautica 194 301 - 308 0094-5765 2022/05 [Refereed][Not invited]
  
• Nonequilibrium Shock Layer in Large-Scale Arc-Heated Wind Tunnel

  Yusuke Takahashi, Hideto Takasawa, Kazuhiko Yamada, Takayuki Shimoda

  Journal of Physics D: Applied Physics 55 (23) 235205 - 235205 0022-3727 2022/03/02 [Refereed][Not invited]
   

  An arc-heated wind tunnel is one of the most important facilities to reproduce the high-temperature environment during atmospheric entry for plasma studies and spacecraft development. However, the properties of the plasma flow cannot be determined easily, because of the complex physical phenomena, such as arc discharge and supersonic expansion, occurring inside the tunnel. The shock-layer structure should be clarified to evaluate the aerodynamic characteristics, communication conditions, and thermal- protection performance in a high-temperature environment. In this study, shock-layer spectroscopic measurements of a plasma flow in a 1 MW-class arc-heated wind tunnel were performed. The γ-band system spectra of nitric oxide (NO) molecules in the ultraviolet region were measured, and the rotational temperature was determined via spectral fitting through comparison with numerical spectra. The rotational temperature of the NO molecules in the shock layer was 6,620±350 K, whereas that in the free jet was much lower at 770±60 K. This difference is attributed to the increase in translational temperature by flow stagnation across the shock wave, followed by the increase in rotational temperature owing to energy relaxation. A computational science approach revealed the detailed structure of the flow through comparisons with the spectroscopic measurement data. The wind tunnel flow became hypersonic with high temperature and low pressure due to the expansion and acceleration at the nozzle and test chamber. Although the temperature increased across the shock wave, the chemical reaction progressed slowly owing to the low-pressure environment. The rotational temperature in the shock layer increased with the translational temperature; this agrees with the trend of the measurement results. The arc-heated flow was found to be in strong thermo- chemical nonequilibrium in the shock layer. Through this study, a detailed structure of arc-heated flow was revealed and its methodology was also proposed.
• Multiphysics Mathematical Modeling and Flow Field Analysis of an Inflatable Membrane Aeroshell in Suborbital Reentry

  Minghao Yu, Zeyang Qiu, Bo Lv, Yusuke Takahash

  Mathematics 10 (5) 832 - 846 2022 [Refereed][Not invited]
  
• Experimental demonstration and mechanism of mitigating reentry blackout via surface catalysis effects

  Hideto Takasawa, Yusuke Takahashi, Nobuyuki Oshima, Hisashi Kihara

  Journal of Physics D: Applied Physics IOP Publishing 54 (22) 225201 - 225201 0022-3727 2021/03/08 [Refereed]
   

  The reentry blackout phenomenon, which is the communication cut-off between the re-entry vehicle and ground station, is a crucial problem that needs to be addressed. To improve safety during reentry, a new mitigation method was proposed using the surface catalysis effect. However, this method has not been investigated extensively by experimental methods. In this study, we experimentally demonstrated the mitigation method using a 1 MW arc-heated wind tunnel and numerically clarified the mitigation mechanism. As a demonstration experiment, communication tests were conducted to compare the two cases. In the first case, a ceramic surface was used as a low catalytic wall, whereas in the second case, a copper surface was used as a high catalytic wall in the arc-heated wind tunnel. The experimental results indicated that the blackout occurred when alumina was used as the low catalytic wall. On the other hand, for the high catalytic wall using copper, blackout was avoided. The tests were reproduced in the wind tunnel using a numerical simulation technique. From the simulation results, the mitigation mechanism suggested that: (a) the number of nitrogen and oxygen atoms decreased due to catalysis; (b) forward reactions of electron impact ionization were suppressed due to the decrease in the number of atoms; and (c) the suppression of reactions decreased the number of electrons, thereby mitigating the reentry blackout. In addition, the numerical simulations performed on the reentry plasma around the re-entry capsule suggested that the mitigation mechanisms between the arc-heated wind flow and reentry plasma were similar despite the different airflow conditions.
• Flow Enthalpy of Nonequilibrium Plasma in 1 MW Arc-Heated Wind Tunnel

  Yusuke Takahashi, Naoya Enoki, Taiki Koike, Mayuko Tanaka, Kazuhiko Yamada, Takayuki Shimoda

  AIAA Journal 59 (1) 263 - 275 0001-1452 2021/01 [Refereed]
   

  The flow enthalpy of an arc-heated wind tunnel is an important parameter for reproducing planetary entry and performing heating tests. However, its distribution is insufficiently clarified, owing to complicated phenomena, such as arc discharge and supersonic expansion. In this paper, the authors assess the enthalpy of an arc-heated flow in a large-scale facility based on measurements and computational results. The flow enthalpy of high-temperature gases, which comprised thermal, chemical, kinetic, and pressure components, was reconstructed based on the measured rotational temperature, heat flux, and impact pressure, in addition to the computational science approach. The rotational temperature of nitric oxide molecules was obtained using emission spectroscopic measurements of band spectra in the near-ultraviolet range. A numerical model was developed and validated based on measured data. The results indicated that the model efficiently reproduced the arc discharge behavior in the heating section and the thermochemical nonequilibrium in the expansion section. It was discovered that the dominant components of the arc-heated flow in the test section were the chemical and kinetic components. The flow enthalpy exhibited a nonuniform distribution in the radial direction. The authors conclude that the flow enthalpy of the core is approximately 28 MJ/kg at the nozzle exit.
• Aerodynamic instability of an inflatable aeroshell in suborbital re-entry

  Yusuke Takahashi, Tatsushi Ohashi, Nobuyuki Oshima, Yasunori Nagata, Kazuhiko Yamada

  Physics of Fluids AIP Publishing 32 (7) 075114 - 075114 1070-6631 2020/07/01 [Refereed]
   

  Aerodynamic instability in the attitude of an inflatable re-entry vehicle in the subsonic regime has been observed during suborbital re-entry. This causes significant problems for aerodynamic decelerators using an inflatable aeroshell; thus, mitigating this problem is necessary. In this study, we revealed the instability mechanism using a computational science approach. To reproduce the in-flight oscillation motion in an unsteady turbulent flow field, we adopted a large-eddy simulation approach with a forced-oscillation technique. Computations were performed for two representative cases at transonic and subsonic speeds that were in stable and unstable states, respectively. Pitching moment hysteresis at a cycle in the motion was confirmed for the subsonic case, whereas such hysteresis did not appear for the transonic case. Pressures on the front surface and in the wake of the vehicle were obtained by employing a probe technique in the computations. Pressure phase delays at the surface and in the wake were confirmed as the pitch angle of the vehicle increased (pitch up) and decreased (pitch down), respectively. In particular, we observed that the wake structure formed by a large recirculation behavior significantly affected the pressure phase delay at the rear of the vehicle. The dynamic instability at subsonic speed resulted from flows that could not promptly follow the vehicle motion. Finally, the damping coefficients were evaluated for the design and development of the inflatable vehicle.
• Surface catalysis effects on mitigation of radio frequency blackout in orbital reentry

  Yusuke Takahashi, Naoya Enoki, Hideto Takasawa, Nobuyuki Oshima,

  Journal of Physics D: Applied Physics 53 (23) 235203 - 235203 0022-3727 2020/04 [Refereed][Not invited]
   

  Radio frequency (RF) blackout during atmospheric reentry leads to the cutoff of communication with ground stations and/or data-relay satellites. This causes significant problems during reentry, and thus, mitigation methods have been in high demand. In this study, we numerically demonstrate a novel method for mitigating the RF blackout using surface catalysis effects. Plasma flow behavior and electromagnetic wave propagation around a reentry vehicle were investigated in detail. The approach couples computational fluid dynamics and a frequency-dependent finite-difference time-domain method. The computations were performed with a massive parallelization technique using a large computer. The computed results were compared for cases imposing low and full catalysis conditions on a surface boundary. The investigation revealed that the surface catalysis effects reduce the RF blackout. Atomic species, dissociated across a shock wave formed in front of the vehicle, were recombined on the vehicle surface through surface catalysis. These molecules, flowing into a wake region at the vehicle's rear, caused recombinations of electrons, originally generated in the shock layer. Therefore, a decrease in electrons was observed in the wake region and a wake path, which allows the propagation of electromagnetic waves, was formed. This complicated behavior of the molecules and electrons, induced by the surface catalysis, resulted in mitigation of the RF blackout.
• Aerodynamics of inflatable nano-satellite “EGG” in low earth orbit and reentry duration

  Naoya Enoki, Yusuke Takahashi, Nobuyuki Oshima, Kazuhiko Yamada, Kojiro Suzuki

  AIP Conference Proceedings American Institute of Physics 2132 100002  0094-243X 2019/08/05 [Refereed][Not invited]
   

  An inflatable nano-satellite with thin-membrane aeroshell, "EGG", was deployed from the International Space Station at an altitude of approximately 400 km, as part of an orbital deployment mission in 2017. After flight on the low Earth orbit (LEO) for 120 days, EGG successfully reentered Earth's atmosphere and burned out according to mission schedule. During the mission period, surface temperatures of the membrane aeroshell of EGG were measured using thermocouples. The measurement data was sent to the ground station using Iridium short burst data communication. There has not been sufficient investigation of the aerodynamic heating environment of such inflatable vehicles. In this paper, the heat flux on membrane aeroshell was revealed, based on the measured temperature data and a heat conduction simulation technique. In addition, heat flux distributions at an altitude of 120 km were numerically evaluated using the Direct Simulation Monte Carlo (DSMC) method, for cases where the angle of attack was between 0 and 180 degrees. From the reconstructed heat flux history and the DSMC analysis results, it was found that the heat flux on the inflatable torus was higher than that on the membrane aeroshell. Additionally, it was concluded that EGG was in the heating environment of approximately 3-4 kW/m(2) at an altitude of 110 km.
• Aerothermodynamic Analysis for Deformed Membrane of Inflatable Aeroshell in Orbital Reentry Mission

  Yusuke Takahashi, Taiki Koike, Nobuyuki Oshima, Kazuhiko Yamada

  Aerospace Science and Technology 92 858 - 868 1270-9638 2019 [Refereed][Not invited]
   

  An inflatable aerodynamic decelerator with a membrane aeroshell is a promising key technology in the reentry, descent, and landing phases of future space transportation. The membrane aeroshell is generally deformed by the in-flight aerodynamic force; however, the effects of the deformation on the aerodynamic heating are unclear. Here, we investigated aerodynamic heating for an inflatable reentry vehicle, Titans, in the hypersonic regime using flow field simulation coupled with structural analysis. Thermochemical nonequilibrium flows around the Titans with a deformed membrane aeroshell were reproduced numerically for an angle of attack (AoA) values between 0 degrees and 40 degrees. The maximum displacements of the membrane aeroshell by deformation at the AoAs of 0 degrees and 40 degrees were 6.7% and 6.6% of the diameter of the Titans, respectively. The difference in heat fluxes between the deformed and rigid shapes was a remarkable 188.8% for a 0 degrees AoA owing to the considerable changes in the front shock wave shape. Meanwhile, it was indicated that membrane deformation at an AoA of 40 degrees insignificantly affected the peak heat flux value on the inflatable torus because the considerable change in the shock wave shape observed for the case of 0 degrees AoA did not occur. It was found that local wrinkles on the membrane aeroshell were formed by deformation, thus causing the heat flux to increase owing to an increase in local temperature gradient on the surface. (C) 2019 Elsevier Masson SAS. All rights reserved.
• Drag Behavior of an Inflatable Reentry Vehicle in the Transonic Regime

  Yusuke Takahashi, Manabu Matsunaga, Nobuyuki Oshima, Kazuhiko Yamada

  Journal of Spacecraft and Rockets 56 (2) 577 - 585 0022-4650 2019 [Refereed][Not invited]
   

  The drag coefficient for inflatable reentry vehicles shows discrepancies between a wind tunnel experiment and a flight test in a transonic regime. These discrepancies exist in the drag decrease behavior in the transonic regime and local minimum values of drag above the sonic speed in a wind tunnel. Hence, the present paper focuses on uncovering the reasons and mechanisms behind the same and investigates transonic flowfields around a vehicle by using a transonic wind tunnel and the computational fluid dynamics approach. Several test models with diameters ranging from 56 to 96 mm are used to quantitatively evaluate the effects of scale and a sting attached on the rear. Aerodynamic coefficients, pressures at the rear of the model, and density-gradient distributions are measured for operation conditions of freestream Mach numbers ranging between 0.8 and 1.3. In addition, detailed distributions of the flowfield properties are clarified using the computational fluid dynamics method, which is validated by the experimental data. The results indicate that a sting behind the test models reduces the steep drag decrease at transonic speeds and that shock waves reflected on the test-section walls of the wind tunnel result in local minimum values at supersonic speeds.
• Spectroscopic Measurement of Air Plasma Flow Generated by 10 kW Class ICP Heater

  Mayuko Tanaka, Kazuhiko Yamada, Yusuke Takahashi, Yu Minghao, Asei Tezuka

  Journal of the Japan Society for Aeronautical and Space Sciences 67 (2) 42 - 48 1344-6460 2019 [Refereed][Not invited]
  
• Experimental Estimation of Rear-side Heat Flux of Hayabusa Sample Return Capsule

  Yasuhisa FUKUDA, Takahiro ARAYA, Yusuke TAKAHASHI, Kazuhiko YAMADA, Jun KOYANAGI

  Koku-Uchu-Gijyutsu (Aerospace Technology Japan, the Japan Society for Aeronautical and Space Sciences) 18 127 - 131 1884-0477 2019 [Refereed][Not invited]
  
• Aerodynamic heating of inflatable aeroshell in orbital reentry

  Yusuke Takahashi, Kazuhiko Yamada

  Acta Astronautica 152 437 - 448 0094-5765 2018/11 [Refereed][Not invited]
   

  The aerodynamic heating of an inflatable reentry vehicle, which is one of the innovative reentry technologies, was numerically investigated using a tightly coupled approach involving computational fluid dynamics and structure analysis. The fundamentals of a high-enthalpy flow around the inflatable reentry vehicle were clarified. It was found that the flow fields in the shock layer formed in front of the vehicle were strongly in a chemical nonequilibrium state owing to its low-ballistic coefficient trajectory. The heat flux tendencies on the surface of the vehicle were comprehensively investigated for various effects of the vehicle shape, surface catalysis, and turbulence via a parametric study of these parameters. In addition, based on the present results of the computational approach, a new heating-rate method was developed to calculate the heat flux of the nonequilibrium flow. It was demonstrated that the method could well-reproduce the heat flux on the inflatable reentry vehicle.
• Aerodynamic instability of flare-type membrane inflatable vehicle in suborbital reentry demonstration

  Tatsushi Ohashi, Yusuke Takahashi, Hiroshi Terashima, Nobuyuki Oshima

  Journal of Fluid Science and Technology 13 (3) JFST0020 - JFST0020 2018/10 [Refereed][Not invited]
   

  An inflatable membrane reentry vehicle has been developed as one of the innovative reentry technologies. A suborbital reentry demonstration using a sounding rocket was carried out in 2012. Contrary to the result of a preliminary study, the vehicle always had an angle of attack (AoA) during its reentry. In addition, the amplitude of AoA gradually increased as altitude decreased, and the vehicle rotated vertically under Mach number of 0.1 (M0.1). As a first step to clarify the cause of attitude instability and vertical rotation, the aerodynamic characteristics, that concern static stability, are numerically investigated. Numerical simulations were carried out for the cases of Mach 0.9 (M0.9), 0.6 (M0.6), 0.3 (M0.3), and 0.1 (M0.1) and pitching moment coefficients (CM) were obtained. Analysis software "RG-FaSTAR" for M0.9, and "FrontFlow/red" for M0.6, M0.3 and M0.1, are used, respectively. Large eddy simulation (LES) was performed using the standard Smagorinsky model to resolve highly unsteady flow features. Because the slope of CM with respect to AoA was negative for all cases, it was found that the vehicle is statically stable. For M0.9, M0.6 and M0.3 cases, absolute values of CM were almost the same. On the other hand, for M0.1, CM had a particularly large value, because the surface pressure distribution on rear side of the vehicle was different from the other cases. This difference was attributed to the separation point on the lower torus moving backward and turbulence in wake being enhanced with a decrease in Mach number and an increase in the Reynolds number.
• Aerodynamic-heating analysis of sample-return capsule in future trojan-asteroid exploration

  Yusuke Takahashi, Kazuhiko Yamada

  Journal of Thermophysics and Heat Transfer 32 (3) 547 - 559 0887-8722 2018 [Refereed][Not invited]
   

  In sample-return missions, the reentry velocity of a sample-return capsule is expected to be approximately 15 km/s however, the reentry velocity of the Hayabusa sample-return capsule was 11.8 km/s. Strong aerodynamic heating caused by a high velocity can damage the capsule during reentry. To overcome this, two designs of highvelocity reentry capsules were proposed. In one design, a rigid flare was attached to decrease the ballistic coefficient by increasing the front projected area. In the other design, the conventional Hayabusa sample-return capsule was used with no modifications. In this study, the aerodynamic heating of the high-velocity reentry capsules and the Hayabusa sample-return capsule was analyzed using numerical simulations. Plasma flow in the shock layer at the front of the capsules and expansion flow in the wake region around the capsules were investigated. The profiles of convective and radiative heat fluxes on the surfaces of these capsules were predicted. The heat fluxes at the stagnation points predicted by the present numerical simulation were in good agreement with that of the empirical models. At the strongest aerodynamic-heating altitude, the total heat fluxes at the rear of the high-velocity reentry capsules and the Hayabusa sample-return capsule were approximately 2% of those in front of the capsules.
• Reentry blackout prediction for atmospheric reentry demonstrator mission considering uncertainty in chemical reaction rate model

  Minseok Jung, Hisashi Kihara, Ken-Ichi Abe, Yusuke Takahashi

  Physics of Plasmas 25 (1) 013507  1089-7674 2018/01/01 [Refereed][Not invited]
   

  A numerical simulation model of plasma flows and electromagnetic waves around a vehicle was developed to predict a radio frequency blackout. Plasma flows in the shock layer and the wake region were calculated using a computational fluid dynamics technique with a three-dimensional model. A finite-catalytic wall condition known to affect plasma properties, such as the number density of electrons, was considered for accurate prediction. A parametric study was performed to investigate the effect of uncertainty in the chemical reaction rate model on evaluating a radio frequency blackout. The behavior of electromagnetic waves in plasma was investigated using a frequency-dependent finite-difference time-domain method. Numerical simulations of reentry blackout were performed for the Atmospheric Reentry Demonstrator mission at various altitudes. The plasma flows and the complex movement of electromagnetic waves around the Atmospheric Reentry Demonstrator vehicle were clarified. The predicted signal loss profile was then directly compared with the experimental flight data to validate the present models. The numerical results generally reproduced the trends over altitudes of the measured data. It is suggested that the present simulation model can be used to investigate the radio frequency blackout and signal loss of electromagnetic waves in the communication of a reentry vehicle. It was confirmed that high associative ionization reaction rates contribute to reducing the electron density in the wake region and radio frequency blackout. It is suggested that the accuracy of predicting the signal loss improved when considering the uncertainty in the chemical reaction model for associative ionizations.
• Aerodynamic Heating Analysis for Inflatable Reentry Vehicle

  高橋裕介, 松永学, 大島伸行, 山田和彦

  日本航空宇宙学会誌 65 (12) 370 - 376 0021-4663 2017/12 [Refereed][Not invited]
  
• Plasma flow modeling for Huels-type arc heater with turbulent diffusion

  Yusuke Takahashi, Burkard Esser, Lars Steffens, Ali Guelhan

  PHYSICS OF PLASMAS 24 (12) 123509  1070-664X 2017/12 [Refereed][Not invited]
   

  In this study, we developed an analytical model for the flow field in the Huels-type arc-heated wind tunnel (L2K) of the German Aerospace Center. This flow-field model can be used to accurately reproduce the discharge behavior in the heating section and expansion in the nozzle section of L2K. It includes the radiation transport and turbulent flow as well as thermochemical nonequilibrium models, which are tightly coupled with electric field calculations. In addition, we considered the turbulent diffusion model for the mass conservation of the species and performed numerical simulations for several cases with and without the turbulent diffusion model. Computations were conducted to obtain the general characteristics of an arc-heated flow containing an arc discharge and supersonic expansion. We verified that radiation and turbulence play important roles in the transfer of heat from the high-temperature core flow to the outer cold gas in the heating section of L2K. In addition, we performed parametric studies that involved varying the degree of turbulent diffusion. The results showed that turbulent diffusion has a large influence on the formation of the arc discharge in the heating section and on the enthalpy distribution at the nozzle exit. Published by AIP Publishing.
• Methods for Determining Nozzle-Throat-Erosion History in Hybrid Rockets

  Landon Kamps, Yuji Saito, Ryosuke Kawabata, Masashi Wakita, Tsuyoshi Totani, Yusuke Takahashi, Harunori Nagata

  Journal of Propulsion and Power American Institute of Aeronautics and Astronautics 33 (6) 1369 - 1377 0748-4658 2017/11 [Refereed][Not invited]
  
• Research, Development and Flight Demonstrations of Deployable Membrane Aeroshell for Atmospheric Entry System

  YAMADA Kazuhiko, SUZUKI Kojiro, ABE Takashi, AKITA Daisuke, IMAMURA Osamu, NAGATA Yasunori, TAKAHASHI Yusuke

  Aeronautical and Space Sciences Japan 一般社団法人 日本航空宇宙学会 65 (11) 333 - 340 0021-4663 2017/11 [Refereed][Not invited]
   

  展開型柔軟エアロシェルは，将来の革新的な大気圏突入システムとして期待されている．我々のグループでは，カプセル形状の本体の周りに取り付けられる円錐形状の薄膜フレアと，その外周に取り付けられたガス圧で展開し形状を維持するインフレータブルリングで構成される，薄膜フレア型の展開型柔軟エアロシェルに注目して研究開発を進めてきた．本技術に対する我々の研究開発活動の特徴は，大気球実験，観測ロケット実験，国際宇宙ステーション/「きぼう」からの超小型衛星の放出機会など，各種フライト機会を利用し，その都度，フライト実験機を開発し，実際に飛行させることで，各要素技術のフライト環境での実証や大気圏突入システムとしての機能検証を行ってきた点にある．本稿では，展開型大気圏突入機の研究開発の紹介とともに，我々がこれまでに行ってきた各種フライト試験の概要について紹介する．

• Aerodecelerator Performance of Flare-Type Membrane Inflatable Vehicle in Suborbital Reentry

  Yusuke Takahashi, Dongheun Ha, Nobuyuki Oshima, Kazuhiko Yamada, Takashi Abe, Kojiro Suzuki

  JOURNAL OF SPACECRAFT AND ROCKETS 54 (5) 993 - 1004 0022-4650 2017/09 [Refereed][Not invited]
   

  A flight experiment of an inflatable reentry vehicle, equipped with a thin-membrane aeroshell deployed by an inflatable torus structure, was performed using a Japan Aerospace Exploration Agency S-310-41 sounding rocket. The drag coefficient history was evaluated by analyzing the acceleration of the vehicle with the atmospheric density and temperature using a global reference atmospheric model. The vehicle successfully demonstrated deceleration. During the reentry flight, the position, velocity, and acceleration of the vehicle were obtained by using the Global Positioning System. The experimental drag coefficient had an almost constant value of 1.5 in the supersonic region but decreased to 1.0 in the subsonic region. In the transonic region, a steep decrease of the drag coefficient was confirmed. To study the detailed aerodynamics for the reentry vehicle, flowfield simulations were conducted with computational fluid dynamics techniques. The aerodynamic force acting on the vehicle was investigated with the measured data throughout the supersonic and subsonic regions. In the flowfield simulation, the computed result for the drag coefficient showed reasonable agreement with the experimental one. In addition, a compressible effect in front of the vehicle was seen to appear in the supersonic region and a vortex ring at the rear of the vehicle was formed in the subsonic region.
• Numerical simulation of plasma flows and radio-frequency blackout in atmospheric reentry demonstrator mission

  Minseok Jung, Minseok Jung, Hisashi Kihara, Hisashi Kihara, Ken Ichi Abe, Ken Ichi Abe, Yusuke Takahashi

  47th AIAA Fluid Dynamics Conference, 2017 2017/01/01 [Refereed][Not invited]
   

  © 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. Numerical simulations of plasma flows and electromagnetic waves around a reentry vehicle were performed to estimate the radio-frequency blackout. The plasma flows in the shock layer and wake region were calculated using computational fluid dynamics technique. The simulation of electromagnetic waves around a reentry vehicle was conducted using a frequency-dependent finite-difference time-domain method with the plasma properties obtained by computational fluid dynamics. The numerical simulations were performed for the atmospheric reentry demonstrator at various altitudes based on the reentry orbit data. Three cases of the numerical simulations, i.e., an axisymmetric model, a three-dimensional model with non-catalytic wall and finite-catalytic wall, were performed for evaluating the effects of angle of attack and catalytic wall on the radio-frequency blackout. The formations for the number density of electrons that is an important parameter in evaluating the radio-frequency blackout were greatly changed by these three cases. The simulation model was validated based on the signal loss history of the experimental flight data. The simulation results using a three-dimensional model with finite-catalytic wall showed better agreement with the measured results compared to other two cases.
• LARGE-EDDY SIMULATION WITH A NEW FLAMELET MODEL FOR PARTIALLY PREMIXED COMBUSTION IN A GAS-TURBINE COMBUSTOR

  Keisuke Tanaka, Tomonari Sato, Nobuyuki Oshima, Jiun Kim, Yusuke Takahashi, Yasunori Iwai

  PROCEEDINGS OF THE ASME POWER CONFERENCE JOINT WITH ICOPE-17, 2017, VOL 1 2017 

  Turbulent combustion flows in the partially premixed combustion field of a dry low-emission gas-turbine combustor were investigated numerically by large-eddy simulation with a 2-scalar flamelet model. Partially premixed combustion was modelled with 2-scalar coupling based on the conservative function of the mixture fraction and the level set function of the premixed flame surface; the governing equations were then used to calculate the gas temperature in the combustion field with flamelet data. A new combustion model was introduced by defining a nondimensional equilibrium temperature to permit the calculation of-adiabatic flame temperatures in the combustion field. Furthermore, a conventional G-equation was modified to include spatial gradient terms for the adiabatic flame temperature to facilitate smooth propagation of a burnt state region in a predominantly diffusion flame. The effect of flame curvature was adjusted by means of an arbitrary parameter in the equation. The simulation results were compared with those from an experiment and a conventional model. Qualitative comparisons of the instantaneous flame properties showed a dramatic improvement in the new combustion model. Moreover, the experimental outlet temperature agreed well with that predicted by the new model. The model can therefore reproduce the propagation of a predominantly diffusion flame in partially premixed combustion.
• Flow-field differences and electromagnetic-field properties of air and N-2 inductively coupled plasmas

  Minghao Yu, Kazuhiko Yamada, Yusuke Takahashi, Kai Liu, Tong Zhao

  PHYSICS OF PLASMAS 23 (12) 123523  1070-664X 2016/12 [Refereed][Not invited]
   

  A numerical model for simulating air and nitrogen inductively coupled plasmas (ICPs) was developed considering thermochemical nonequilibrium and the third-order electron transport properties. A modified far-field electromagnetic model was introduced and tightly coupled with the flow field equations to describe the Joule heating and inductive discharge phenomena. In total, 11 species and 49 chemical reactions of air, which include 5 species and 8 chemical reactions of nitrogen, were employed to model the chemical reaction process. The internal energy transfers among translational, vibrational, rotational, and electronic energy modes of chemical species were taken into account to study thermal nonequilibrium effects. The low-Reynolds number Abe-Kondoh-Nagano k-epsilon turbulence model was employed to consider the turbulent heat transfer. In this study, the fundamental characteristics of an ICP flow, such as the weak ionization, high temperature but low velocity in the torch, and wide area of the plasma plume, were reproduced by the developed numerical model. The flow field differences between the air and nitrogen ICP flows inside the 10-kW ICP wind tunnel were made clear. The interactions between the electromagnetic and flow fields were also revealed for an inductive discharge. Published by AIP Publishing.
• Numerical analysis on the effect of angle of attack on evaluating radio-frequency blackout in atmospheric reentry

  Minseok Jung, Hisashi Kihara, Ken-ichi Abe, Yusuke Takahashi

  JOURNAL OF THE KOREAN PHYSICAL SOCIETY 68 (11) 1295 - 1306 0374-4884 2016/06 [Refereed][Not invited]
   

  A three-dimensional numerical simulation model that considers the effect of the angle of attack was developed to evaluate plasma flows around reentry vehicles. In this simulation model, thermochemical nonequilibrium of flowfields is considered by using a four-temperature model for high-accuracy simulations. Numerical simulations were performed for the orbital reentry experiment of the Japan Aerospace Exploration Agency, and the results were compared with experimental data to validate the simulation model. A comparison of measured and predicted results showed good agreement. Moreover, to evaluate the effect of the angle of attack, we performed numerical simulations around the Atmospheric Reentry Demonstrator of the European Space Agency by using an axisymmetric model and a three-dimensional model. Although there were no differences in the flowfields in the shock layer between the results of the axisymmetric and the three-dimensional models, the formation of the electron number density, which is an important parameter in evaluating radio-frequency blackout, was greatly changed in the wake region when a non-zero angle of attack was considered. Additionally, the number of altitudes at which radio-frequency blackout was predicted in the numerical simulations declined when using the three-dimensional model for considering the angle of attack.
• Analysis of Radio Frequency Blackout for a Blunt-Body Capsule in Atmospheric Reentry Missions

  Yusuke Takahashi, Reo Nakasato, Nobuyuki Oshima

  Aerospace 3 (1) 2 - 2 2226-4310 2016/01 [Refereed][Not invited]
  
• Advanced validation of CFD-FDTD combined method using highly applicable solver for reentry blackout prediction

  Yusuke Takahashi

  JOURNAL OF PHYSICS D-APPLIED PHYSICS 49 (1) 015201  0022-3727 2016/01 [Refereed][Not invited]
   

  An analysis model of plasma flow and electromagnetic waves around a reentry vehicle for radio frequency blackout prediction during aerodynamic heating was developed in this study. The model was validated based on experimental results from the radio attenuation measurement program. The plasma flow properties, such as electron number density, in the shock layer and wake region were obtained using a newly developed unstructured grid solver that incorporated real gas effect models and could treat thermochemically non-equilibrium flow. To predict the electromagnetic waves in plasma, a frequency-dependent finite-difference time-domain method was used. Moreover, the complicated behaviour of electromagnetic waves in the plasma layer during atmospheric reentry was clarified at several altitudes. The prediction performance of the combined model was evaluated with profiles and peak values of the electron number density in the plasma layer. In addition, to validate the models, the signal losses measured during communication with the reentry vehicle were directly compared with the predicted results. Based on the study, it was suggested that the present analysis model accurately predicts the radio frequency blackout and plasma attenuation of electromagnetic waves in plasma in communication.
• Aerodynamic Heating Around Flare-Type Membrane Inflatable Vehicle in Suborbital Reentry Demonstration Flight

  Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe, Kojiro Suzuki

  JOURNAL OF SPACECRAFT AND ROCKETS 52 (6) 1530 - 1541 0022-4650 2015/11 [Refereed][Not invited]
   

  A demonstration flight of an advanced reentry vehicle was carried out using a sounding rocket. The vehicle was equipped with a flexible (membrane) aeroshell deployed by an inflatable torus structure. Its most remarkable feature was the low ballistic coefficient that enables reduction in aerodynamic heating and deceleration at a high altitude. During the suborbital reentry, temperatures at several locations on a backside of the flexible aeroshell and inside the capsule were measured by means of embedded thermocouples. The aerodynamic heating behavior of the vehicle was investigated using the measured temperature history, in combination with a numerical prediction in which a flow-field simulation of the heating was conducted. In this flow-field simulation, both laminar flow and turbulent flow were assumed, and the deformation of the flexible aeroshell was considered. A thermal model of the capsule and membrane aeroshell was developed, and the heat flux profiles of the vehicle surface during aerodynamic heating were constructed based on the measured temperatures. The measured temperature data were found to be in reasonable agreement with the predicted data if the flow field near the capsule of the vehicle was assumed to be laminar, with a transition to turbulent flow near the membrane aeroshell.
• Thermochemical Nonequilibriu.m 2D Modeling of Nitrogen Inductively Coupled Plasma Flow

  Yu Minghao, Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe, Kazuhiko Yamada, Takashi Abe, Satoshi Miyatani

  PLASMA SCIENCE & TECHNOLOGY 17 (9) 749 - 760 1009-0630 2015/09 [Refereed][Not invited]
   

  Two-dimensional (2D) numerical simulations of thermochemical nonequilibrium inductively coupled plasma (ICP) flows inside a 10-kW inductively coupled plasma wind tunnel (ICPWT) were carried out with nitrogen as the working gas. Compressible axisymmetric NavierStokes (N-S) equations coupled with magnetic vector potential equations were solved. A fourtemperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles. The third-order accuracy electron transport properties (3rd AETP) were applied to the simulations. A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process. The flow characteristics such as thermal nonequilibrium, inductive discharge, effects of Lorentz force were made clear through the present study. It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field. The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT.
• Computation and analysis of the electron transport properties for nitrogen and air inductively-coupled plasmas

  Minghao Yu, Hisashi Kihara, Ken-ichi Abe, Yusuke Takahashi

  JOURNAL OF THE KOREAN PHYSICAL SOCIETY 66 (12) 1833 - 1840 0374-4884 2015/06 [Refereed][Not invited]
   

  A relatively simple method for calculating accurately the third-order electron transport properties of nitrogen and air thermal plasmas is presented. The electron transport properties, such as the electrical conductivity and the electron thermal conductivity, were computed with the best and latest available collision cross-section data in the temperature and pressure ranges of T = 300 - 15000 K and p = 0.01 - 1.0 atm, respectively. The results obtained under the atmospheric pressure condition showed good agreements with the experimental and the high-accuracy theoretical results. The presently-introduced method has good application potential in numerical simulations of nitrogen and air inductively-coupled plasmas.
• Accuracy verification of the turbulent flame les model by a methane/air burner flame

  Murase Kagenobu, Oshima Nobuyuki, Takahashi Yusuke

  ASME/JSME/KSME 2015 Joint Fluids Engineering Conference, AJKFluids 2015 1A 2015 

  This paper focuses on the numerical simulation of Sandia National Laboratories "the piloted methane/air burner flame D." Large Eddy Simulation and 2-scalar flamelet approach are applied for the turbulent and partially premixed combustion field, which is expressed by the LES filtered equations of scalar G for tracking the flame surfaces and mixture fraction of a fuel and an oxidizer. The flamelet data consists of temperature, specific volume and laminar flame speed are calculated by the detail chemical reaction with GRI-Mech 3.0. Two kinds of flamelet data are validated one is "equilibrium flamelet data" calculated by 0-dimensional equilibrium solution based on equilibrium model the other is "diffusion flamelet data" calculated by 1-dimensional counter flow solution based on laminar flamelet model. Consequently, the "diffusion flamelet data" gives better result in this type of combustion field.
• Numerical study of plasma flow around a reentry vehicle during atmospheric reentry with an unstructured grid solver

  Reo Nakasato, Yusuke Takahashi, Nobuyuki Oshima

  ASME/JSME/KSME 2015 Joint Fluids Engineering Conference, AJKFluids 2015 1A 2015 

  When a reentry vehicle enters the planetary atmosphere, a strong shock wave is generated and the strong aerodynamic heating appears. Gas temperature in front of the vehicle exceeds 10,000K and chemical reactions (ionizations and dissociations) occur behind the shock wave. Because the reentry vehicle is damaged by the aerodynamic heating, accurate evaluation of the aerodynamic heating in the high-enthalpy flow is necessary for the design and the development of the vehicle. The communication blackout phenomenon which prevents the propagation of the electromagnetic waves can occur by the characteristics of electrons in the shock layer to absorb and reflect the electromagnetic waves. To estimate the communicationable time and understand the behavior of the electromagnetic waves around the vehicle, the accurate evaluation of the plasma flow around the vehicle is also necessary. In this study, the three-dimensional numerical analysis was conducted to consider an angle of attack by using the analysis software for compressible fluid, RG-FaSTAR which has been developed by JAXA. Moreover, unstructured grids were used to make it easier to generate computational grid around the vehicle with complicated shape. Note that RG-FaSTAR is a version of FaSTAR (FaST Aerodynamic Routine) installing the real gas effect. We reproduced the actual flow field around the Atmospheric Reentry Demonstrator (ARD) which was launched by the European Space Agency (ESA) in 1998 and revealed the aerodynamic heating and plasma flow properties during atmospheric reentry. The computational result showed good agreement with measured pressure coefficient at the stagnation point. In addition, the features of the shock layer and the rear region around ARD were revealed.
• Aerodynamic Simulation of Inflatable Re-Entry Vehicle Performance in Low Speed Wind Tunnel

  Dongheun HA, Yusuke TAKAHASHI, Kazuhiko YAMADA, Takashi ABE

  Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 12 (ists29) Po_2_57 - Po_2_62 1884-0485 2014/12 [Refereed][Not invited]
   

  An inflatable re-entry vehicle is a candidate for future re-entry systems. Owing to the large area and configuration of the vehicle, it can afford a few advantages during the re-entry, descent, and landing approach, such as a decrease of aerodynamic heating and soft landing without requiring a parachute system. To investigate aerodynamic characteristics of inflatable reentry vehicle at low-Mach-number flight, wind tunnel tests were performed in JAXA Low-Speed-Wind tunnel. In this research, we investigated aerodynamic characteristics of 2 types of inflatable reentry vehicle, SMAAC and TITANS, at a low-Mach-number by using numerical simulation. Through the flow field simulation, it was indicated that the computed result of drag coefficient shows reasonable agreement with the experimental one. In the case of TITANS, the computed results showed good agreements compared with experimental results though it was confirmed that a blockage effect was observed.
• Prediction Performance of Blackout and Plasma Attenuation in Atmospheric Reentry Demonstrator Mission

  Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe

  JOURNAL OF SPACECRAFT AND ROCKETS 51 (6) 1954 - 1964 0022-4650 2014/11 [Refereed][Not invited]
   

  A numerical simulation model that combines the plasma flows and electromagnetic waves around a reentry vehicle during atmospheric reentry was developed to evaluate the radio frequency blackout and plasma attenuation. The physical properties of the plasma flow in the shock layer and wake region were obtained using a computational fluid dynamics technique. The electromagnetic waves were expressed using a frequency-dependent finite difference time domain method with the plasma properties. Combined simulations were performed for the atmospheric reentry demonstrator of the ESA at various altitudes based on reentry orbit data. The electromagnetic wave behaviors around the vehicle during atmospheric reentry were investigated in detail. Moreover, a parametric analysis with different ionization reaction models was performed. It was confirmed that the vehicle is surrounded by the plasma and the propagation of the electromagnetic waves is prevented at high altitude. Then, the plasma is dissipated and the propagation recovers at low altitude. Validation of the simulation model was performed based on the plasma attenuation history of the experimental flight data. A comparison of the measured and predicted results showed good agreement. It was concluded that the combined simulation model could be an effective tool for investigating the radio frequency blackout and the plasma attenuation of radio wave communication.
• Numerical Investigation of Flow Fields in Inductively Coupled Plasma Wind Tunnels

  Yu Minghao, Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe, Kazuhiko Yamada, Takashi Abe

  PLASMA SCIENCE & TECHNOLOGY 16 (10) 930 - 940 1009-0630 2014/10 [Refereed][Not invited]
   

  Numerical simulations of 10 kW and 110 kW inductively coupled plasma (ICP) wind tunnels were carried out to study physical properties of the flow inside the ICP torch and vacuum chamber with air as the working gas. Two-dimensional compressible axisymmetric NavierStokes (N-S) equations that took into account 11 species and 49 chemical reactions of air, were solved. A heat source model was used to describe the heating phenomenon instead of solving the electromagnetic equations. In the vacuum chamber, a four-temperature model was coupled with N-S equations. Numerical results for the 10 kW ICP wind tunnel are presented and discussed in detail as a representative case. It was found that the plasma flow in the vacuum chamber tended to be in local thermochemical equilibrium. To study the influence of operation conditions on the flow field, simulations were carried out for different chamber pressures and/or input powers. The computational results for the above two ICP wind tunnels were compared with corresponding experimental data. The computational and experimental results agree well, therefore the flow fields of ICP wind tunnels can be clearly understood.
• Improvement of a Three-Band Radiation Model for Application to Chemical Nonequilibrium Flows

  Naoya Hirata, Masataka Yamada, Hisashi Kihara, Ken-ichi Abe, Yusuke Takahashi

  Journal of Thermophysics and Heat Trasnfer, 28 (4) 709 - 803 0887-8722 2014/10 [Refereed][Not invited]
  
• Examination of Radio Frequency Blackout for an Inflatable Vehicle During Atmospheric Reentry

  Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe

  JOURNAL OF SPACECRAFT AND ROCKETS 51 (2) 430 - 441 0022-4650 2014/03 [Refereed][Not invited]
   

  Numerical simulations of the plasma flow and electromagnetic wave around a membrane-aeroshell type reentry vehicle were performed using various physical model combinations, and the possibility of radio frequency blackout of transceiver antenna embedded at the rear of the vehicle was investigated. The flowfield was assumed to be in thermochemical nonequilibrium, and it was described by the Navier-Stokes equations with a multitemperature model and the equation of state. The simulations were performed for several altitudes, including the highest heat flux point according to reentry orbit data. Through these computations, the detailed distributions of the flowfield properties in the shock layer and wake region were successfully obtained. To evaluate the possibility of radio frequency blackout during atmospheric reentry, the distribution of the electron number density around the inflatable vehicle was clarified. A frequency-dependent finite-difference time-domain method was used for simulations of electromagnetic waves, and the physical properties were obtained from the computational results of the plasma flow calculation. Electromagnetic wave behaviors in an ionized gas region behind the inflatable vehicle were investigated. It was found that the number density of electrons was sufficiently small and that the electromagnetic waves can propagate with no reflection and less attenuation. These results suggest that radio frequency blackout may not occur during the atmospheric reentry of the inflatable vehicle.
• Advanced Validation of Nonequilibrium Plasma Flow Simulation for Arc-Heated Wind Tunnels

  Yusuke Takahashi, Takashi Abe, Hiroki Takayanagi, Masahito Mizuno, Hisashi Kihara, Ken-ichi Abe

  JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER 28 (1) 9 - 17 0887-8722 2014/01 [Refereed][Not invited]
   

  Turbulent plasma flows in arc heaters, such as Japan Aerospace Exploration Agency's 750 kW, NASA's 20 MW, and Kyushu University's 20 kW facilities, were investigated, and the distributions of the flowfield properties were successfully obtained. The arc discharge in the constrictor section and the expansion processes in the nozzle section played key roles in the formation of an arc-heated flow. Hence, for accurately predicting high-enthalpy flow properties, it was important to correctly model the complex phenomena observed in various-scale facilities. For this purpose, an integrated analysis model to simulate various-scale arc-heated flows with high accuracy was developed. The turbulent flowfield was described using the Reynolds-averaged Navier-Stokes equations with a multitemperature model, which was tightly coupled with electric-field and radiation-field calculations. A sophisticated and low-cost radiation model and a low-Reynolds-number two-equation turbulence model were introduced into the flowfield simulation. To validate the present integrated analysis model, the computed results were compared with the corresponding experimental data for the mass-averaged enthalpy, the translational and rotational temperatures, and the number density of nitrogen obtained through spectroscopic and laser-induced fluorescence techniques. Moreover, the mechanisms of energy input by discharge and energy loss are discussed, along with the distributions of the electronic excitation temperature and heat flux on the constrictor wall derived from the arc column. Although the results indicated that a relatively detailed discharge model is required to describe the arc discharge with relatively high accuracy, the present flowfield model was generally in good agreement with various operating conditions of the facilities.
• Numerical simulation of flow field around an inatable vehicle during a reentry demonstration flight

  Dongheun Ha, Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe

  32nd AIAA Applied Aerodynamics Conference 2014 

  A flight experiment of an inatable reentry vehicle, which equips a thin membrane aeroshell deployed by an inatable torus structure, was performed by a JAXA S-310-41 sounding rocket. The vehicle successfully demonstrated deceleration at a high altitude. During the reentry ight, position, velocity and acceleration of the vehicle were obtained by the global positioning system. Moreover, drag coefficient history was evaluated by the acceleration of vehicle with atmospheric density and temperature by a global reference atmospheric model. Experimental drag coefficient was almost constant value of 1.5 in supersonic region, while that decreased to 1.0 in subsonic region. At transonic region, steep decrease of the drag coefficient was confirmed. To study detailed aerodynamics for the reentry vehicle, flow field simulations were conducted with computational uid dynamics techniques. Aerodynamic force acting on the vehicle was investigated with the measured data throughout the supersonic and subsonic regions. In theflow field simulation, it was indicated that the computed result of drag coefficient shows reasonable agreement with the experimental one. In addition, it was clarified that compressible effect in front of the vehicle remarkably appears in supersonic region, and a feature of vortex ring at the rear of the vehicle is formed in subsonic region.
• LARGE-EDDY SIMULATION OF TRANSIENT BEHAVIOR IN A COMBUSTION FIELD FOR GAS-TURBINE ENGINE

  Yusuke Takahashi, Nobuyuki Oshima, Yasunori Iwai

  11TH WORLD CONGRESS ON COMPUTATIONAL MECHANICS; 5TH EUROPEAN CONFERENCE ON COMPUTATIONAL MECHANICS; 6TH EUROPEAN CONFERENCE ON COMPUTATIONAL FLUID DYNAMICS, VOLS V - VI 5792 - 5803 2014 

  Combustion flow field in an industrial gas-turbine combustor was numerically investigated with a newly-developed turbulent combustion model. For turbulent model, large-eddy simulation technique was introduced to simulate unsteady phenomena in detail. The combustion model was based on a two-scalar flamelet approach coupling the two concepts of premixed and non-premixed flames expressed by the conservative scalar of mixture fraction and the levelset function of premixed flame surface, respectively. A fine full tetra computational mesh of 45.5 million cells and 7.7 million nodes was used to resolve turbulent fluctuation with high accuracy in the combustion field. The simulations were performed for two calculation conditions reproducing diffusion-like and premixed-like flames and for three conditions decreasing fuel inlet to investigate flame extinction behavior. It was indicated that premixed or partial premixed turbulent flames by complex burner system in the real scale combustor can be reasonably captured by the present simulation model.
• Numerical Simulation of Nonequilibrium Inductive Plasma Flow Coupled with Electromagnetic Field Calculation

  Minghao Yu, Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe, Kazuhiko Yamada, Takashi Abe

  PROCEEDINGS OF THE 29TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS 1628 1124 - 1131 0094-243X 2014 [Refereed][Not invited]
   

  Numerical investigation of nonequilibrium inductively coupled plasma (ICP) flow was carried out to study the physical properties of the flow inside a 10-kW ICP torch with the working gas being nitrogen. The flow field was described by two-dimensional compressible axisymmetric Navier-Stokes (N-S) equations that took into account 5 species and 8 chemical reactions. The magnetic vector-potential equations were tightly coupled with the flow-field equations to describe the heating process by inductive discharge. A four-temperature model was adopted to model thermal nonequilibrium process in the discharge torch. The characteristics of ICP flow such as thermal nonequilibrium, inductive discharge, and strong effects of Lorentz forces became clear through the present study.
• Numerical prediction of test flow conditions for low density high enthalpy flow in an expansion tube facility

  Takanori Akahori, Katsumi Hiraoka, Yusuke Takahashi, Yasunori Nagata, Kazuhiko Yamada, Takashi Abe

  51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013 2013 

  FLow generated in the expansion tube was numerically simulated to evaluate the test flow conditions including the test flow period. For this purpose, the chemically equilibrium flow is assumed and the boundary layer effect is considered. To identify the start of the test flow period, the contact surface is intentionally detected. The boundary layer generated from the foot of the propagating shock wave was found to significantly modify the flow structure and thus the test flow conditions. The modification of the flow structure due to the tapered nozzle was clarified. Some of the numerical results are validated with the respective experimental measurement. In summary, the test flow conditions and the test flow period were estimated. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Aerodynamic heating around an inflatable vehicle during a reentry demonstration flight by a sounding rocket

  Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe, Kojiro Suzuki

  AIAA Aerodynamic Decelerator Systems (ADS) Conference 2013 2013 [Refereed][Not invited]
   

  A reentry flight demonstration of an advanced reentry vehicle was carried out using a sounding rocket. The vehicle is equipped with a flexible (membrane) aeroshell deployed by an inflatable torus structure. During the reentry flight, temperatures at several locations of a backside of a flexible aeroshell and a sidewall of a capsule were measured by means of embedded thermocouples. Behavior of aerodynamic heating of the vehicle is investigated along with the measured temperature history, combining the numerical prediction in which the numerical flow simulation and the heating estimation based on it were conducted. In the flow field simulation, not only laminar flow but also turbulent flow were assumed, and modification of the flexible aero-shell were considered. It was found that the measured temperature data shows a reasonable agreement with the predicted one if the flow field near the membrane aeroshell of the vehicle is assumed to be turbulent flow. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Improvement of Potential Drop Predictions for Plasma Wind Tunnels by Cathode Sheath

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER 26 (3) 540 - 544 0887-8722 2012/07 [Refereed][Not invited]
  
• Nonequilibrium plasma flow properties in arc-heated wind tunnels

  Yusuke Takahashi, Yusuke Takahashi, Takashi Abe, Takashi Abe, Hiroki Takayanagi, Hiroki Takayanagi, Masahito Mizuno, Masahito Mizuno, Hisashi Kihara, Hisashi Kihara, Ken Ichi Abe, Ken Ichi Abe

  50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition 2012/06/20 [Refereed][Not invited]
   

  Turbulent plasma flows in arc heaters such as JAXA 750 kW, NASA 20 MW and Kyushu University 20 kW facilities were investigated and the distributions of flow-field properties were successfully obtained. For this purpose, an integrated analysis model to simulate various-scale arc-heated flows with high accuracy was developed. The turbulent flow field was described by the Navier-Stokes equations with a multitemperature model, which was tightly coupled with electric-field and radiation-field calculations. An accurate and low-cost radiation model and a low-Reynolds number two-equation turbulence model were introduced into the flow-field simulation. Arc discharge in constrictor section and expansion processes in nozzle section play key roles for forming an arc-heated flow. Thus, it is important to correctly model those phenomena for predicting the high-enthalpy flow properties accurately. To validate the present numerical model, the computed results were compared with the corresponding experimental data for the mass-averaged enthalpy, temperatures and number density. Through the comparison of the predicted results with detailed experimental data obtained by spectroscopic and laser-induced fluorescence techniques, the present integrated analysis model was validated. In addition, the mechanisms of energy input by discharge and energy loss were discussed with distributions of the temperature and heat flux derived from the arc column. Although it was indicated that more detailed discharge model is possibly required in order to describe arc discharge with higher accuracy, the present flow-field model was found to give generally good agreement for various operating conditions of the facilities. © 2012 by the American Institute of Aeronautics and Astronautics, Inc.
• Numerical study of pyrolysis gas flow and heat transfer inside an ablator

  N. Hirata, S. Nozawa, Y. Takahashi, H. Kihara, K. Abe

  Computational Thermal Sciences 4 (3) 225 - 242 1940-2503 2012 [Refereed][Not invited]
   

  A numerical simulation of a lightweight ablator in an arc-heated flow was carried out. Thermal response analysis of the ablator was coupled with thermochemical nonequilibrium analysis of an arc jet around the ablator. In the thermal response analysis, the pyrolysis gas flow inside the ablator was calculated in detail by solving the conservation equations. Phenomena such as heat conduction, pyrolysis of resin, surface reactions, and recession were also considered in the simulation. Furthermore, in order to evaluate the injection of the ablation gas (pyrolysis gas and carbonaceous gas generated by the surface reactions) from the ablator surface into the outer flow field, a computational fluid dynamics code was extended by including further chemical species besides those in the previous study. This also allowed the simulations for wider-range flow conditions such as a nitrogen flow and airflow. The simulation was conducted for flow conditions of a 20 kW arc-heated nitrogen flow and a 750 kW arc-heated airflow. The results from the former simulation were compared with the experimental data and the computational results using other models. This comparison showed that the effect of the pyrolysis gas flow on the thermal response was significant, and thus the detailed analysis considering the multidimensional pyrolysis gas flow led to a considerable improvement of the predictive performance. © 2012 by Begell House, Inc.
• Radio frequency blackout possibility for an inflatable reentry vehicle

  Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe

  42nd AIAA Fluid Dynamics Conference and Exhibit 2012 2012 

  Numerical simulations of a plasma flow around a membrane-aeroshell type reentry vehicle with various physical models combination were performed and radio frequency blackout for transceiver antenna embedded at the rear of the vehicle was investigated. The flow field was assumed to be thermochemical nonequilibrium and was described by the Navier-Stokes equations with a multitemperature model and the equation of state. The simulations were performed for several altitudes including the highest heat flux point according to a reentry orbit data. Through these computations, flow-field properties distributions in shock layer and wake region were successfully obtained in detail. In order to evaluate the radio frequency blackout during atmospheric reentry, distribution of electron number density around the inflatable vehicle were clarified and the RF blackout possibility was discussed. In addition, simulations of electromagnetic waves based on the computational results of the plasma flow calculation were performed with a frequency-dependent finite-difference time-domain method. Electromagnetic wave behaviors in an ionized-gas region behind the inflatable vehicle were investigated. It was seen that the number density of electrons was sufficiently small and the electromagnetic waves can propagate with less reflection and attenuation. From these reasons, we found that the RF blackout hardly occurs during atmospheric reentry. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Turbulence and radiation behaviours in large-scale arc heaters

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  JOURNAL OF PHYSICS D-APPLIED PHYSICS 44 (8) 085203  0022-3727 2011/03 [Refereed][Not invited]
   

  Turbulent plasma flow in large-scale arc heaters such as JAXA 750 kW and NASA 20 MW facilities was investigated and distributions of flow-field properties were successfully obtained. The turbulent flow field was described by the Navier-Stokes equations with a multitemperature model, which was tightly coupled with electric-field and radiation-field calculations. An accurate and low-cost radiation model, and a low Reynolds number two-equation turbulence model were introduced into the flow-field simulation. It was confirmed that the plasma flows in the arc-heating facilities were in a highly thermochemical nonequilibrium state in the expansion section and that the arc discharge plays a critical role in the heating section. It was quantitatively clarified that radiation and turbulence phenomena were very important in transferring heat and momentum from the high-temperature flow near the core to the cold gas region near the facility wall. To confirm the effectiveness of the present numerical model, the obtained results were compared with experimental data for the arc voltage, mass-averaged enthalpy, chamber pressure and heat efficiency. The present flow-field model was found to give good agreement for various operating conditions of the facilities.
• Numerical simulation of flow fields in large-scale segmented-type arc heaters

  Yusuke Takahashi, Hisashi Kihara, Ken Ichi Abe

  27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010 2 1470 - 1479 2010/12/01 [Refereed][Not invited]
   

  Turbulent plasma flow in large-scale arc heater such as NASA 60 MW Interaction Heating Facility was numerically investigated and the distribution of the arc-heated flow-field properties were successfully obtained.The turbulent flow-field was described by the Reynolds- Averaged Navier-Stokes equations with a multitemperature model,tightly coupled with the electric field and the radiation-field calculations. In addition,an accurate and low-cost radiation model and a low-Reynolds number two-equation turbulence model were introduced into the flowfield simulation.It was quantitatively clarified that radiation and turbulence phenomena are very important mechanisms to transfer heat and momentum from high-temperature core region to cold gas region near the wall.To validate the present numerical model,the numerical solutions were compared with the experimental data,e.g.,arc voltage,mass-averaged enthalpy,chamber pressure and heat efficiency.It was indicated that the present flow-field simulation model showed good agreement over various operating conditions of the facilities. © 2010 by the International Council of Aeronautical Sciences - ICAS.
• The effects of radiative heat transfer in arc-heated nonequilibrium flow simulation

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  JOURNAL OF PHYSICS D-APPLIED PHYSICS 43 (18) 185201  0022-3727 2010/05 [Refereed][Not invited]
   

  Numerical simulation of a 20 kW constrictor-type arc-heated flow was carried out, and the distribution of the nonequilibrium flow-field properties was obtained. The flow field was described by the Navier-Stokes equations with a multi-temperature model, tightly coupled with the electric-field and radiation-field calculations. As a radiation model, an accurate and low-cost model was introduced into the flow-field simulation. It was confirmed that the plasma flow inside the arc-heated facility is in a state of high nonequilibrium and the arc discharge plays a critical role. By comparing the computational results with/without the radiation model, it was clarified that the radiation exerts significant effects on the heat transport in the constrictor section. Additionally, to validate the present numerical model, the numerical solutions were compared with the experimental data. It was indicated that the present flow-field simulation with a radiation model tends to be in good agreement with the corresponding experimental data.
• Numerical Investigation of Nonequilibrium Plasma Flows in Constrictor- and Segmented-Type Arc Heaters

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER 24 (1) 31 - 39 0887-8722 2010/01 [Refereed][Not invited]
   

  Numerical simulations are carried out and the distributions of flowfield properties are obtained for nonequilibrium, flows in a 20 kW constrictor-type and a 750 kW segmented-type arc-heated wind tunnel. In these arc heaters, it is confirmed that each plasma flow is highly in nonequilibrium and are discharge plays critical roles. The flowfield is described by the Navier-Stokes equations with a multitemperature model. To validate the present numerical model, the numerical solutions are compared with the corresponding experimental data. The flow characteristics in the 20 and 750 kW arc heaters (e.g., the arc discharge and the supersonic expansion) become clear through the present simulations. In particular, the computed results for the 20 kW arc heater indicate almost full dissociation/ionization reactions and thermochemical equilibrium in the constrictor section, while strong nonequilibrium clearly appears in the nozzle section.
• Numerical Investigation of Thermochemical Nonequililbrium Flow Field in a 20kW Arc Heater Coupled with Electric Field Calculation

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  RAREFIED GAS DYNAMICS 1084 883 - 888 0094-243X 2009 [Not refereed][Not invited]
   

  Numerical simulation is carried out and the distribution of flow field properties is obtained for nonequilibrium flow in a constrictor-type 20kW arc-heated wind tunnel. In the arc heater, plasma flow is highly in nonequilibrium and arc discharge plays a critical role. The flow field is described by the Navier-Stokes equations with a multi-temperature model. The flow field equations are solved with the governing equation for the electric field being coupled. Furthermore, to validate the present numerical model, the numerical solutions are compared with the corresponding experimental data. The flow characteristics in the 20kW arc heater, e.g., the arc charge and the supersonic expansion, become clear through the present simulation. Moreover, the computed results for the arc heater indicate almost full dissociation/ionization reactions and thermochemical equilibrium in the constrictor part, while strong nonequilibrium clearly appears in the nozzle section.

MISC

• Demonstration of deployable aeroshell "Jettison" during the reentry flight (RATS-J)

  YAMADA, Kazuhiko, NAGATA, Yasunori, TAKAHASHI, Yusuke, TAKAYANAGI, Hiroki, NAKAO, Tatsuro, HAMORI, Hitoshi, MORIYOSHI, Takahiro, ISHIMURA, Kosei, SUZUKI, Kojiro  Proceedings of Sounding Rocket Symposium 2023  2024/02  

  誤記: 羽森, 仁 レポート番号: Ⅲ-2
• Overview Report of Free Flight Test of Hayabusa using Scientific Balloon in Australia Hayabusa-Type Larger Sample Return Capsule

  YAMADA, Kazuhiko, ONO, Ryosuke, YAGI, Yuma, NAKAO, Tatsuro, TAKAYANAGI, Hiroki, SUGIMOTO, Ryo, MARU, Yusuke, OZAWA, Takashi, NAGATA, Yasunori, IMAI, Shun, KUBOTA, Sota, NAGAI, Hiroki, TAKAHASHI, Yusuke  Balloon Symposium: 2023  2023/10/01  

  レポート番号: isas23-sbs-004
• Coupling Analysis with Dynamic Mode Decomposition for Reentry Capsule with Thin Aeroshell

  高澤秀人, 高橋裕介, 永田靖典, 山田和彦  宇宙科学技術連合講演会講演集(CD-ROM)  67th-  2023
• はやぶさ型カプセルの遷音速・低速域における空力安定性評価—Evaluation of aerodynamic stability in the transonic and low speed range of Hayabusa-type SRC

  山田, 和彦, 髙栁, 大樹, 中尾, 達郎, 小野, 稜介, 八木, 邑磨, 丸, 祐介, 小澤, 宇志, 永井, 大樹, 高橋, 裕介, 永田, 靖典, 今井, 駿, YAMADA, Kazuhiko, TAKAYANAGI, Hiroki, NAKAO, Tatsuro, ONO, Ryosuke, YAGI, Yuma, MARU, Yusuke, OZAWA, Takashi, NAGAI, Hiroki, TAKAHASHI, Yusuke, NAGATA, Yasunori, IMAI, Shun  大気球シンポジウム: 2022年度 = Balloon Symposium: 2022  2022/11  

  大気球シンポジウム 2022年度（2022年11月7-8日. ハイブリッド開催（JAXA相模原キャンパス& オンライン)) Balloon Symposium 2022 (November 7-8, 2022. Hybrid(in-person & online) Conference (Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan 著者人数: 11名 資料番号: SA6000177011 レポート番号: isas22-sbs-011
• 流体運動連成解析を用いた遷音速域における薄殻型再突入カプセルの空力不安定性—Aerodynamic Instability of Thin Shell Type Reentry Capsule at Transonic Speed Using Coupled Analysis of Unsteady Flow with Pitching Motion

  高澤 秀人, 藤井 智也, 平田 耕志郎, 森吉 貴大, 高橋 裕介, 永田 靖典, 山田 和彦  計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science / 日本計算工学会 編  27-  217  -222  2022/06
• Aerodynamic Instability of Thin Shell Type Reentry Capsule at Transonic Speed Using Coupled Analysis of Unsteady Flow with Pitching Motion

  高澤秀人, 藤井智也, 平田耕志郎, 森吉貴大, 高橋裕介, 永田靖典, 山田和彦  計算工学講演会論文集(CD-ROM)  27-  2022
• Aerodynamic Instability of Thin Shell Type Reentry Capsule Using Coupled Analysis of Unsteady Flow with Pitching Motion

  高澤秀人, 藤井智也, 平田耕志郎, 森吉貴大, 高橋裕介, 永田靖典, 山田和彦  宇宙科学技術連合講演会講演集(CD-ROM)  66th-  2022
• 遷音速風洞実験における柔軟構造エアロシェルのFSI挙動—Fluid Structure Interaction Behavior of Inflatable Aeroshell in Transonic Wind Tunnel Experiments

  戸張, 純希, 若林, 海人, 高橋, 裕介, 森吉, 貴大, 山田, 和彦, TOBARI, Junki, WAKABAYASHI, Kaito, TAKAHASHI, Yusuke, MORIYOSHI, Takahiro, YAMADA, Kazuhiko  令和3年度宇宙航行の力学シンポジウム = Symposium on Flight Mechanics and Astrodynamics: 2021  2021/12  

  令和3年度宇宙航行の力学シンポジウム（2021年12月20日-21日. オンライン開催) Symposium on Flight Mechanics and Astrodynamics: 2021 (December 20-21, 2021. Online Meeting) 資料番号: SA6000174024
• Fluid-Structure Interaction Analysis for Spacecraft in Atmospheric Reentry using Open-source Software

  高橋裕介, 戸帳純希, 石田国宏, 大島伸行, 柴田良一  計算工学講演会論文集(CD-ROM)  26-  2021
• Numerical Study on Mitigation of Reentry Blackout by Effects of Air Film

  宮下岳士, 高澤秀人, 高橋裕介, 大島伸行, STEFFENS Lars, ESSER Burkard, GUELHAN Ali  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  53rd-39th-  2021
• Study on Aerodynamic Instability Mitigation for Hayabusa-type Reentry Capsule using Proper Orthogonal Decomposition

  鶴本徹, 高橋裕介, 寺島洋史, 大島伸行  衝撃波シンポジウム講演論文集(CD-ROM)  2019-  2020
• Overview and Development Status of Nano-Satellite BEAK

  山田和彦, 鈴木宏二郎, 今村宰, 秋田大輔, 永田靖典, 荘司泰弘, 高橋裕介, 森吉貴大  宇宙科学技術連合講演会講演集(CD-ROM)  63rd-  2019
• Study on Aerodynamic Simulation for Martian Exploration Parafoil

  石田国宏, 大橋達志, 高橋裕介, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  51st-37th-  2019
• Numerical Analysis of Mitigation of Reentry Blackout in Arc-Heated Wind Tunnel

  高澤秀人, 高橋裕介, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  51st-37th-  2019
• The Relationship between Wake Flow of the HAYABUSA Type Reentry Capsule and Aerodynamic Stability

  鶴本徹, 高橋裕介, 寺島洋史, 大島伸行  宇宙科学技術連合講演会講演集(CD-ROM)  63rd-  2019
• はやぶさ型再突入カプセルまわりの流れ場とカプセル表面圧力の関係

  鶴本徹, 高橋裕介, 寺島洋史, 大島伸行  数値流体力学シンポジウム講演論文集(CD-ROM)  33rd-  2019
• 1MWアーク加熱風洞における通信ブラックアウト低減化の数値シミュレーション

  高澤秀人, 高橋裕介, 大島伸行, 木原尚  数値流体力学シンポジウム講演論文集(CD-ROM)  33rd-  2019
• 超低軌道における膜面展開型超小型衛星のポストフライト解析

  齊藤雅弘, 高橋裕介, 寺島洋史, 大島伸行  数値流体力学シンポジウム講演論文集(CD-ROM)  33rd-  2019
• 運動連成解析を用いた火星探査パラフォイルの空力特性に関する研究

  石田国宏, 大橋達志, 高橋裕介, 大島伸行  数値流体力学シンポジウム講演論文集(CD-ROM)  33rd-  2019
• 高温衝撃風洞を用いたはやぶさカプセル周りの密度場可視化計測

  内部銀二, 嶋村耕平, 藤原侑介, 原島葵, 高橋裕介, 山田和彦, 丹野英幸, 小室智幸  衝撃波シンポジウム講演論文集(CD-ROM)  2018-  ROMBUNNO.2A2‐1  2019  [Not refereed][Not invited]
  
• Wake Behavior of HAYABUSA Type Reentry Capsule at Subsonic Speed

  高橋裕介, 大橋達志, 丸祐介, 山田和彦  宇宙科学技術連合講演会講演集(CD-ROM)  62nd-  2018
• Aerodynamic Simulation for HAYABUSA Type Reentry Capsule in Transonic Regime

  鶴本徹, 高橋裕介, 寺島洋史, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  50th-36th-  2018
• Dynamics of shock wave and separation region over a forced oscillating airfoil in the transonic flow regime

  榎並聖也, 寺島洋史, 高橋裕介, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  50th-36th-  2018
• Aerodynamic Instability Analysis of HAYABUSA Type Reentry Capsule

  鶴本徹, 高橋裕介, 寺島洋史, 大島伸行  宇宙科学技術連合講演会講演集(CD-ROM)  62nd-  2018
• 柔軟構造再突入機の空力加熱について

  高橋裕介, 小池太輝, 大島伸行  日本機械学会年次大会講演論文集(CD-ROM)  2018-  2018
• Aerodynamic Instability Analysis of HAYABUSA Type Reentry Capsule

  鶴本徹, 高橋裕介, 寺島洋史, 大島伸行  日本機械学会流体工学部門講演会講演論文集(CD-ROM)  96th-  2018
• Aerodynamic stability of flare-type thin-membrane inflatable aeroshell in suborbital reentry

  大橋達志, 高橋裕介, 寺島洋史, 大島伸行  日本機械学会流体工学部門講演会講演論文集(CD-ROM)  96th-  2018
• Mitigation of Radio Frequency Blackout during Atmospheric Reentry using Surface Catalytic Effect

  榎尚也, 高橋裕介, 大島伸行  日本機械学会流体工学部門講演会講演論文集(CD-ROM)  96th-  2018
• Outline of EGG mission (Re-Entry Nano-Satellite with Gossamer Aeroshell and GPS/Iridium)

  今村宰, 森吉貴大, 松丸和誉, 金丸拓樹, 荒谷貴洋, 山田和彦, 鈴木宏二郎, 秋田大輔, 永田康典, 莊司泰弘, 高橋裕介, 渡邊保真, 安部隆士  宇宙科学技術連合講演会講演集(CD-ROM)  61st-  2017
• Development and Operational quick report of Nanosatellite EGG (re-Entry Satellite with Gossamer aeroshell and GPS/Iridium)

  山田和彦, 森吉貴大, 松丸和誉, 金丸拓樹, 荒谷貴洋, 鈴木宏二郎, 今村宰, 秋田大輔, 永田靖典, 莊司泰弘, 高橋裕介, 渡邊保真, 安部隆士  宇宙科学技術連合講演会講演集(CD-ROM)  61st-  2017
• 観測ロケットを用いた柔軟構造体の再突入試験における空力不安定性解析

  大橋達志, 松永学, 高橋裕介, 寺島洋史, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  49th-35th-  2017
• 柔軟構造体に対する再突入ブラックアウトの数値解析

  榎尚也, 松永学, 高橋裕介, 寺島洋史, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  49th-35th-  2017
• 大気圏再突入用柔軟構造エアロシェルの空力加熱解析

  小池太輝, 高橋裕介, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  49th-35th-  2017
• Aerodynamic Analysis of Reflection Chamber Airfoil in Low-density Environment

  大橋達志, 高橋裕介, 大島伸行, 山田和彦  宇宙科学技術連合講演会講演集(CD-ROM)  61st-  2017
• Aerodynamic Simulation for Nano-Satellite “EGG” during Atmospheric Reentry

  高橋裕介, 榎尚也, 大島伸行, 山田和彦, 鈴木宏二郎  宇宙科学技術連合講演会講演集(CD-ROM)  61st-  2017
• 衝撃波はく離を伴う遷音速強制振動翼周りの非定常流れ場構造と空力予測について

  榎並聖也, 寺島洋史, 高橋裕介, 大島伸行  数値流体力学シンポジウム講演論文集(CD-ROM)  31st-  2017
• Analysis Model of Aerodynamic Heating Prediction for Inflatable Reentry Vehicle in Hypersonic Flow Region

  高橋 裕介, 松永 学, 山田 和彦  年会講演会講演集  47-  8p  2016/04/14
• パラフォイル型飛翔体における翼特性が飛行安定性に及ぼす効果に関する研究—The Effect of the Airfoil Characteristics on Flight Stability for the Parafoil-Type Vehicle

  森吉 貴大, 前川 啓, 金丸 拓樹, 山田 和彦, 原田 大樹, 高橋 裕介, 安部 隆士  年会講演会 = JSASS annual meeting  47-  7p  2016/04
• パラフォイル型飛翔体における翼特性が飛行安定性に及ぼす効果に関する研究

  森吉貴大, 前川啓, 金丸拓樹, 山田和彦, 原田大樹, 高橋裕介, 安部隆士  日本航空宇宙学会年会講演会講演集(CD-ROM)  47th-  2016
• Plasma Flow and Electromagnetic Waves Analysis around ESA ARD during Atmospheric Reentry

  中里玲王, 高橋裕介, 大島伸行  宇宙航空研究開発機構特別資料 JAXA-SP-  (15-013)  2016
• ISAS1MWアーク加熱風洞におけるアーク加熱気流について

  高橋裕介, 松永学, 山田和彦, 下田孝幸  衝撃波シンポジウム講演論文集(CD-ROM)  2015-  2016
• ICOPE-15-1124 Numerical Investigation of Turbulent Combustion Flow in Industrial Combustor with Flamelet Approach

  Sasaki Tenshi, Takahashi Yusuke, Oshima Nobuyuki, Iwai Yasunori  Proceedings of the International Conference on Power Engineering : ICOPE  2015-  (12)  "ICOPE  -15-1124-1"-"ICOPE-15-1124-11"  2015/11/30  

  In this paper, an industrial gas-turbine combustor was numerically investigated by applying large-eddy simulation for turbulent model and 2-scalar flamelet approach for combustion model. In the combustion model, the structures of premixed and non-premixed flame are expressed by conservative scalar and levelset function respectively. These two concepts are coupled for partial premixed combustion field. Flow field properties inside the flame (temperature, density, laminar flame speed) are determined by "flamelet data". The flamelet data is mainly divided in "premixed-like flamelet data" and "diffusion-like flamelet data" in this study. The premixed-like flamelet data is based on chemical equilibrium assumption and is evaluated by 0-dimensional chemical reaction calculation. On the other hand, the diffusion-like flamelet data is based on laminar flamelet assumption and is evaluated by 1-dimensional counter flow combustion calculation. In this study, for the diffusion-like combustion field in the industrial combustor, diffusion-like flamelet data was newly applied. The predicted gas temperature showed a little higher value than the temperature calculated by using the premixed-like flamelet data. However, the predicted temperatures underestimated measured one. Therefore, in this case, it was cleared that difference of flamelet data is insignificant for improving analysis accuracy.
• 大気球突入機用柔軟エアロシェル開発における大気球実験

  山田 和彦, 安部 隆士, 鈴木 宏二郎, 今村 宰, 秋田 大輔, 永田 靖典, 高橋 裕介, MAAC研究開発グループ, Yamada Kazuhiko, Abe Takashi, Suzuki Kojiro, Imamura Osamu, Akita Diasuke, Nagata Yasunori, Takahashi Yusuke, MAAC Research Group  大気球シンポジウム: 平成27年度 = Balloon Symposium: 2015  2015/11  

  大気球シンポジウム 平成27年度（2015年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000044004レポート番号: isas15-sbs-004
• Rarefied Gas Dynamics Simulation for Membrane Inflatable Small Satellite "EGG" at Ultra Low Orbit

  高橋 裕介, 山田 和彦, 鈴木 宏二郎  宇宙科学技術連合講演会講演集  59-  5p  2015/10/07
• Aerodynamic simulation of Closed-Canopy-Type Parafoil for Martian Exploration Mission at High Angle of Attack

  原田 大樹, 高橋 裕介, 大島 伸行  宇宙科学技術連合講演会講演集  59-  6p  2015/10/07
• S1910201 Aerodynamic Simulation of Inflatable Reentry Vehicle in Transonic Wind Tunnel

  MATSUNAGA Manabu, HA Dongheun, TAKAHASHI Yusuke, OSHIMA Nobuyuki, YAMADA Kazuhiko  Mechanical Engineering Congress, Japan  2015-  "S1910201  -1"-"S1910201-5"  2015/09/13  

  A reentry flight experiment of a new type reentry vehicle was carried out using JAXA S-310-41 sounding rocket. The vehicle was equipped a thin membrane aeroshell deployed by an inflatable torus structure and demonstrated deceleration at high altitude. Before the flight experiment, a wind tunnel test was conducted to obtain aerodynamic characteristics. It was found that drag coefficient data measured in the flight experiment and wind tunnel test shows different tendency in transonic region. In the present study, flow field simulations around the wind tunnel model focused on sting effect were conducted. In the flow field simulations, the drag coefficient of wind tunnel test and calculation showed good agreement, and it was clarified that major reason of drag coefficient difference is existence of sting. It is difficult to obtain drag coefficient of inflatable reentry vehicle without sting using wind tunnel in transonic region. It is useful to use numerical method.
• Validation of High-Enthalpy Flow Prediction around ESA ARD during Atmospheric Reentry with an Unstructured Grid Solver

  中里玲王, 高橋裕介, 大島伸行, 溝渕泰寛, 村上桂一  宇宙航空研究開発機構特別資料 JAXA-SP-  (14-010)  2015
• 大気圏再突入時におけるESA ARD周りのプラズマ流・電磁波解析

  中里玲王, 高橋裕介, 大島伸行  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  47th-33rd-  2015
• Characterization of JAXA/ISAS Arc Wind Tunnel Facility

  下田孝幸, 山田和彦, 高橋裕介  宇宙航空研究開発機構特別資料 JAXA-SP-  (14-010)  2015
• Study on aerodynamic characteristics of a martian close-canopy-type parafoil at low Reynolds number

  原田 大樹, 高橋 裕介, 大島 伸行  宇宙科学技術連合講演会講演集  58-  5p  2014/11/12
• 大型柔軟エアロシェルによる大気突入回収システムの実証試験

  山田 和彦, 安部 隆士, 鈴木 宏二郎, 今村 宰, 秋田 大輔, 永田 靖典, 高橋 裕介, Yamada Kazuhiko, Abe Takashi, Suzuki Kojiro, Imamura Osamu, Akita Diasuke, Nagata Yasunori, Takahashi Yusuke  大気球シンポジウム: 平成26年度 = Balloon Symposium: 2014  2014/11  

  大気球シンポジウム 平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000021009レポート番号: isas14-sbs-009
• ISSからの放出衛星（EGG）の搭載機器の動作および運用確認試験

  今村 宰, 山田 和彦, 鈴木 宏二郎, 安部 隆士, 秋田 大輔, 永田 靖典, 高橋 裕介, Imamura Osamu, Yamada Kazuhiko, Suzuki Kojiro, Abe Takashi, Akita Diasuke, Nagata Yasunori, Takahashi Yusuke  大気球シンポジウム: 平成26年度 = Balloon Symposium: 2014  2014/11  

  大気球シンポジウム 平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000021010レポート番号: isas14-sbs-010
• S1910104 Prediction Performance of Plasma Flow and RF Blackout around a Reentry Vehicle with an Angle of Attack

  TAKAHASHI Yusuke, RAURELL Daniel Sors, OSHIMA Nobuyuki  Mechanical Engineering Congress, Japan  2014-  "S1910104  -1"-"S1910104-5"  2014/09/07  

  Numerical prediction model of plasma flow and electromagnetic waves around a reentry vehicle was validated based on experimental results of the radio attenuation measurement program (RAM-CII). Through the plasma flow simulations, the detailed distributions of the flow-field properties in the shock layer and wake region were successfully obtained by three-dimensional unstructured grid solver (FaSTAR) to consider angle of attack of the vehicle. The flow-field solver installed real gas effect models and could treat thermochemically nonequilibrium flow. Moreover, the distribution of the electron number density around the vehicle was clarified. A frequency-dependent finite-difference time-domain (FD2TD) method was used for simulations of electromagnetic waves. In the simulation, the physical properties were obtained from the results of the plasma flow calculation. In the present study, electromagnetic wave behaviors in an ionized gas region around the reentry vehicle were investigated in detail. Prediction performance of the combined model was evaluated with profile of the electron number density near the vehicle surface and a signal loss measured in communication between the vehicle and ground station.
• ISSから放出される柔軟構造エアロシェルを有する再突入機の開発

  奥田謙太朗, 森吉貴大, 土井翔平, 宮谷聡, 山田和彦, 鈴木宏二郎, 安部隆士, 永田靖典, 今村宰, 秋田大輔, 高橋裕介  宇宙科学技術連合講演会講演集(CD-ROM)  58th-  2014
• 大気圏突入時におけるESA ARD周りの高エンタルピー流に関する非構造格子解析モデルの検証

  中里玲王, 高橋裕介, 大島伸行, 溝渕泰寛, 村上桂一  流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)  46th-32nd-  2014
• 大気再突入機の通信ブラックアウト予測モデルの検証

  高橋裕介, JHA Abhinav Kumar, 大島伸行, 山田和彦  宇宙科学技術連合講演会講演集(CD-ROM)  58th-  2014
• メタン空気バーナー火炎を対象とした乱流燃焼モデルの精度検証

  村瀬景信, 大島伸行, 高橋裕介  燃焼シンポジウム講演論文集  52nd-  2014
• 実機燃焼器における乱流燃焼場のLES/Flameletアプローチ

  高橋裕介, 大島伸行, 岩井保憲  数値流体力学シンポジウム講演論文集(CD-ROM)  28th-  2014
• JAXA相模原アーク風洞の特性評価

  下田孝幸, 山田和彦, 高橋裕介  宇宙科学技術連合講演会講演集(CD-ROM)  58th-  2014
• 柔軟エアロシェルの地球再突入実証ミッション提案

  山田 和彦, 安部 隆士, 永田 靖典, 高橋 裕介, 秋田 大輔, 今村 宰, 鈴木 宏二郎, 柔軟構造大気突入機(MAAC)研究グループ, Yamada Kazuhiko, Abe Takashi, Nagata Yasunori, Takahashi Yusuke, Akita Daisuke, Imamura Osamu, Suzuki Kojiro  宇宙航行の力学シンポジウム: 平成24年度 = Symposium on Flight Mechanics and Astrodynamics: 2012  136  -139  2013/12  

  平成24年度宇宙航行の力学シンポジウム（2012年12月13日-14日. 宇宙航空研究開発機構宇宙科学研究所）, 相模原市, 神奈川県資料番号: SA6000010033
• 膨張波管を用いた高エンタルピー流れにおける電磁シールド効果の検証

  服部盛正, 嶋津悠介, 手塚亜聖, 高橋裕介, 永田靖典, 上野一磨, 山田和彦, 安部隆士  衝撃波シンポジウム講演論文集  2012-  117  -120  2013/03/13  [Not refereed][Not invited]
  
• G201 Thermal Response Analysis of a Light-weight Ablator in Superorbital Reentry Environment

  HIRATA Naoya, NOZAWA Sohei, TAKAHASHI Yusuke, YAMADA Masataka, KIHARA Hisashi, ABE Ken-ichi  Fluids engineering conference ...  2012-  467  -468  2012/11/16  

  Thermal response analysis of a light-weight ablator coupled with radiating flow-field analysiswas carried out. Pyrolysis-gas flow inside the light-weight ablator, which has relatively high porosity, should show characteristics different from that inside a traditional heavy ablator. Moreover, the effect of pyrolysis-gas flow is considered to be large in the lightweight ablator. Therefore, in the thermal response analysis, the pyrolysis-gas flow inside the ablator was calculated in detail. For the calculation condition, the flight environment of Hayabusa capsule was used. The results showed multi-dimensional aspects for the pyrolysis-gas flow and thus the detailed analysis such as used in this paper is essential for the analysis of a light-weight ablator.
• The Scale Effect of the Interaction between a High-Enthalpy Flow and a Magnetized Body

  Hattori Morimasa, Makino Hitoshi, Nagata Yasunori, Takahashi Yusuke, Yamada Kazuhiko, Abe Takashi  宇宙航空研究開発機構特別資料: 第43回流体力学講演会: 航空宇宙数値シミュレーション技術シンポジウム2011論文集 = JAXA Special Publication: Proceedings of 43rd Fluid Dynamics Conference / Aerospace Numerical Simulation Symposium 2011  (11)  107  -112  2012/03/30  

  43rd Fluid Dynamics Conference / Aerospace Numerical Simulation Symposium 2011 (July 7-8, 2011. Waseda University, International Conference Center), Tokyo JapanFor a high-enthalpy flow, it has been suggested that shock layer formed by the body in a weakly-ionized flow is enhanced as a result of the interaction between a magnetic field applied to the body and the flow. According to the theory, the scale effect of the interaction is organized by the interaction parameter defined by the ratio of the magnetic force to inertial force of the flow, which includes not only the intensity of the applied magnetic field but also the flow parameters such as density. In this study, the scale effect of the interaction is investigated experimentally, by varying not only the intensity of the applied magnetic field but also other parameters. For this purpose, the high-enthalpy flow generated in the expansion tube is employed. It was confirmed that the influence on the shock layer by the interaction is almost proportional to the interaction parameter as the theory suggests.Physical characteristics: Original contains color illustrations
• 1715 Performance of Reynolds-Averaged Turbulence Models for Predicting Flow Fields in Large-Scale Arc-Heated Wind Tunnels

  TAKAHASHI Yusuke, KIHARA Hisashi, ABE Ken-ichi  Fluids engineering conference ...  2010-  507  -508  2010/10/29  

  Turbulent plasma flow in a large-scale arc heater was numerically investigated and the distributions of the arc-heated flow-field properties were successfully obtained. The turbulent flow field was described by the Navier-Stokes equations with a multi-temperature model, tightly coupled with the electric-field and radiation-field calculations. As for radiation and turbulence models, an accurate and low-cost radiation model and a low-Reynolds number two-equation turbulence model were introduced into the flow-field simulation. It was confirmed that the plasma flow inside the arc-heating facilities was in a state of high nonequilibrium in the expansion section and the arc discharge plays a critical role in the heating section. It was quantitatively clarified that the radiation and turbulence phenomena were very important mechanisms to transfer heat and momentum from high-temperature flow near the core to cold gas region near the facility wall.

Books etc

• Encyclopedia of Plasma Technology

  Yusuke Takahashi (ContributorArc-Heated Wind Tunnel)
  CRC Press, Taylor & Francis Group 2017/02 (ISBN: 146650059X) 1728

Presentations

• Study on Mitigation of Reentry Blackout by Surface Catalysis Effects in Arc-Heated Wind Tunnel  [Not invited]

  Hideto Takasawa, Yusuke Takahashi, Nobuyuki Oshima, Hisashi Kihara

  Aerospace Europe Conference 2020,  2020/02  Bordeaux
• 再突入ブラックアウト低減化に向けた数値的研究  [Invited]

  高橋裕介

  日本学術会議第9回計算力学シンポジウム  2019/12
• Numerical Analysis of Aerodynamic Instability for HAYABUSA Type Reentry Capsule  [Not invited]

  Toru TSURUMOTO, Yusuke TAKAHASHI, Hiroshi TERASHIMA, Nobuyuki OSHIMA

  8TH EUROPEAN CONFERENCE FOR AERONAUTICS AND SPACE SCIENCES (EUCASS)  2019/07  Madrid
• Aerodynamics of Inflatable Nano-Satellite “EGG” in Low Earth Orbit and Reentry Duration  [Not invited]

  Naoya Enoki, Yusuke Takahashi, Nobuyuki Oshima, Kazuhiko Yamada, Kojiro Suzuki

  31st Internal Symposium on Rarefied Gas Dynamics  2018/07
• 大気再突入時における宇宙機の空力・空力加熱について  [Invited]

  高橋裕介, 小池太輝

  北海道大学-JAXA連携企画講演会・HASTIC学術技術講演会  2018/03
• Aerodynamic heating prediction of flare-type membrane inflatable reentry vehicle from low earth orbit  [Not invited]

  Taiki Koike, Yusuke Takahashi, Nobuyuki Oshima, Kazuhiko Yamada

  AIAA Atmospheric Flight Mechanics Conference, 2018  2018  American Institute of Aeronautics and Astronautics Inc, AIAA
   

  Aerodynamic heating around a flare-type membrane inflatable vehicle during Earth atmospheric reentry was investigated using numerical simulation approach. This vehicle, which is mainly composed of the capsule, membrane aeroshell and inflatable torus, has been developed by the Membrane Aeroshell for Atmospheric-entry Capsule (MAAC) group as a one of the innovative reentry systems. Analysis solver for reentry flows around the vehicle was RG-FaSTAR, which is a branch version of JAXA fast aerodynamic routine (FaSTAR). In addition, structure analysis solver also was used for membrane deformation in a loosely-coupled manner with the flow field. In the present research, the effects of angle of attack (AoA) and membrane aeroshell deformation on aerodynamic heating were investigated. The numerical results showed that heat flux distribution drastically varies with the increase in AoA because of changes of flow field, and heat flux value at the stagnation point for case of AoA of 40 degree was 3.09 times as high as that for 0 degree. Moreover, the deformed shapes for case of AoA of 0 and 40 degrees were calculated in the way which the pressure distributions obtained using initial (undeformed) shape were given as the aerodynamic force. The difference of heat fluxes between the deformed and initial shapes on the head capsule part was remarkable as 188.8% for case of AoA of 0 degree. On the other hand, it was indicated that membrane deformation for case of AoA of 40 degree insignificantly affects the peak heat flux value on the inflatable torus such as the case of the AoA of 0 degree.
• Aerodynamic Heating Prediction of Flare-type Membrane Inflatable Reentry Vehicle from Low Earth Orbit  [Not invited]

  Taiki Koike, Yusuke Takahashi, Nobuyuki Oshima, Kazuhiko Yamada

  2018 AIAA Atmospheric Flight Mechanics Conference, AIAA SciTech Forum  2018/01
• Aerodynamic Instability of Flare-type Membrane Inflatable Vehicle in Suborbital Reentry Demonstration  [Not invited]

  Tatsushi OHASHI, Manabu MATSUNAGA, Yusuke TAKAHASHI, Hiroshi TERASHIMA, Nobuyuki OSHIMA

  The Ninth JSME-KSME Thermal and Fluids Engineering Conference (TFEC9)  2017/10
• Prediction of electromagnetic waves around an inflatable reentry vehicle in an atmospheric reentry mission  [Not invited]

  Naoya ENOKI, Manabu MATSUNAGA, Yusuke TAKAHASHI, Hiroshi TERASHIMA, Nobuyuki OSHIMA, Kazuhiko YAMADA, Kojiro SUZUKI

  The Ninth JSME-KSME Thermal and Fluids Engineering Conference (TFEC9)  2017/10
• Large-Eddy Simulation with a New Flamelet Model for Partially Premixed Combustion in a Gas-Turbine Combustor  [Not invited]

  Keisuke Tanaka, Tomonari Sato, Nobuyuki Oshima, Jiun Kim, Yusuke Takahashi, Yasunori Iwai

  the ASME 2017 Power and Energy Conference  2017/06
• Numerical Simulation of Plasma Flows and Radio-Frequency Blackout in Atmospheric Reentry Demonstrator Mission  [Not invited]

  Minseok Jung, Hisashi Kihara, Ken-ichi Abe, Yusuke Takahashi

  47th AIAA Fluid Dynamics Conference, AIAA AVIATION Forum  2017/06
• Aerodynamic Heating Prediction of an Inflatable Reentry Vehicle in a Hypersonic Wind Tunnel  [Not invited]

  Manabu Matsunaga, Yusuke Takahashi, Nobuyuki Oshima, Kazuhiko Yamada

  55th AIAA Aerospace Sciences Meeting  2017/01
• Aerodynamic heating prediction of an inflatable reentry vehicle in a hypersonic wind tunnel  [Not invited]

  Manabu Matsunaga, Yusuke Takahashi, Nobuyuki Oshima, Kazuhiko Yamada

  AIAA SciTech Forum - 55th AIAA Aerospace Sciences Meeting  2017  American Institute of Aeronautics and Astronautics Inc.
   

  Aerodynamic heating around an inflatable reentry vehicle was investigated using hypersonic wind tunnel and numerical approach. The inflatable reentry vehicle is mainly composed of the capsule, membrane aeroshell (rigid in the wind tunnel), and inflatable torus. Basic configuration of the reentry vehicle (HWT-MAAC) is a scaled-down model of SMAAC, which was used in demonstration mission with JAXA / ISAS S-310-41 sounding rocket. Spherical cap of the SMAAC model was replaced by blunt top. Freestream condition of Mach number of 10, reservoir pressure of 2.5 MPa, and reservoir temperature of 950 K was used in the hypersonic wind tunnel test. Heat flux distribution on the surface and density gradient around the HWT-MAAC were measured by infrared thermography and Schliren photograph techniques, respectively. It was found that heat flux distribution widely varies according to angle of attack of the vehicle and a recirculation region near the membrane aeroshell section of the vehicle can appear at high angle of attack. Flow field was also numerically simulated with computational fluid dynamics approach. Analysis solver used here in was RG-FaSTAR, which is a version of JAXA fast aerodynamic routine (FaSTAR). Structures of shock layer and expansion region around HWT-MAAC was discussed through the analysis approach and the wind tunnel results.
• NUMERICAL INVESTIGATION OF ABLATION EFFECT ON AERODYNAMIC HEATING FOR HIGH VELOCITY REENTRY CAPSULE  [Not invited]

  Manabu Matsunaga, Takahiro Sasaki, Yusuke Takahashi, Nobuyuki Oshima

  The 27th International Symposium on Transport Phenomena (ISTP27)  2016/09
• NUMERICAL ANALYSIS OF RADIO FREQUENCY BLACKOUT FOR ATMOSPHERIC REENTRY VEHICLE USING CFD-CEM COMBINED METHOD  [Not invited]

  Yusuke Takahashi, Reo Nakasato, Nobuyuki Oshima

  VII European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2016)  2016/06  Crete Island, Greece
• Numerical analysis of radio frequency blackout for atmospheric reentry vehicle using CFD-CEM combined method  [Not invited]

  Yusuke Takahashi, Reo Nakasato, Nobuyuki Oshima

  ECCOMAS Congress 2016 - Proceedings of the 7th European Congress on Computational Methods in Applied Sciences and Engineering  2016  National Technical University of Athens
   

  Numerical simulations of electromagnetic waves around the atmospheric reentry demonstrator (ARD) of the European Space Agency (ESA) in an atmospheric reentry mission were conducted with a combined method of computational fluid dynamics (CFD) and computational electromagnetics (CEM). During the reentry mission, radio frequency blackout and plasma attenuation of radio waves in communications with a data-relay satellite were observed. Cut-off of waves propagation was caused by highly dense plasma formed by a strong shock wave formed in front of the vehicle due to orbital speed. In this study, the physical properties of the plasma flow in the shock layer and wake region of the ESA ARD were obtained using a high-enthalpy flow solver applicable unstructured grids. Moreover, electromagnetic waves were calculated using a frequency-dependent finite-difference time-domain method using the plasma properties. The present analysis model was validated based on experimental flight data of ESA ARD. Comparisons of the measured and predicted results showed good agreements. Attenuation and reflection by reentry plasma were clarified in detail using the present model. It was suggested that the analysis model could be an effective tool for investigating radio frequency blackout and plasma attenuation in radio wave communication. Behaviors of plasma and electromagnetic waves around ESA ARD for several altitudes were investigated using the proposed model in detail.
• Development of Analysis Tools for Space Vehicle in Atmospheric Reentry Mission  [Invited]

  Yusuke Takahashi, Nobuyuki Oshima

  Korea-Japan CFD Workshop 2015  2015/12
• Numerical Investigation of Turbulent Combustion Flow in Industrial Combustor with Flamelet Approach  [Not invited]

  Tenshi Sasaki, Yusuke Takahashi, Nobuyuki Oshima, Yasunori Iwai

  International Conference on Power Engineering-15 (ICOPE-15)  2015/11  Yokohama, Japan
• Accuracy Verification of the Turbulent Flame LES Model by a Methane/Air Burner Flame  [Not invited]

  Kagenobu Murase, Nobuyuki Oshima, Yusuke Takahashi

  ASME-JSME-KSME Joint Fluids Engineering Conference 2015  2015/07  Seoul, Korea
• Aerodynamic Simulation of Closed-Canopy-Type Parafoil for Martian Exploration Mission  [Not invited]

  Daiki Harada, Yusuke Takahashi, Nobuyuki Oshima, Kazuhiko Yamada

  ASME-JSME-KSME Joint Fluids Engineering Conference 2015  2015/07  Seoul, Korea
• Numerical Study of Plasma Flow around a Reentry Vehicle during Atmospheric Reentry with an Unstructured Grid Solver  [Not invited]

  Reo Nakasato, Yusuke Takahashi, Nobuyuki Oshima

  ASME-JSME-KSME Joint Fluids Engineering Conference 2015  2015/07  Seoul, Korea
• Large-Eddy Simulation of Transient Behavior in a Combustion Field for Gas-Turbine Engine  [Not invited]

  Yusuke Takahashi, Nobuyuki Oshima, Yasunori Iwai

  ytakahashi@eng.hokudai.ac.jp  2014/07
• Numerical Simulation of Flow Field around an Inflatable Vehicle during a Reentry Demonstration Flight  [Not invited]

  Dongheun Ha, Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe

  AIAA-2014-3283  2014/06
• Numerical Investigation of Flow Fields in Inductively Coupled Plasma Wind Tunnel  [Not invited]

  Minghao Yu, Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe, Kazuhiko Yamada, Takashi Abe

  4th Asian Symposium on Computational Heat Transfer and Fluid Flow  2013/06
• Aerodynamic Simulation of an Inflatable Re-Entry Vehicle Performance in Low Speed Wind Tunnel  [Not invited]

  Dongheun Ha, Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe

  29th International Symposium on Space Technology and Science  2013/06
• Aerodynamic Heating around an Inflatable Vehicle during a Reentry Demonstration Flight by a Sounding Rocket  [Not invited]

  Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe, Kojiro Suzuki

  AIAA-2013-1303  2013/03
• Numerical Evaluation of Nonequilibrium Plasma Flow in 1kW Class Arc Thruster  [Not invited]

  Minghao YU, Yusuke TAKAHASHI, Ken-ichi ABE, Hisashi KIHARA

  5th International Symposium on Advanced Plasma Science and its Applications for Nitrides and Nanomaterials  2013/01
• Numerical Prediction of Test Flow Conditions for Low Density High Enthalpy Flow in an Expansion Tube Facility  [Not invited]

  Takanori Akahori, Katsumi Haraoka, Yusuke Takahashi, Yasunori Nagata, Kazuhiko Yamada, Takashi Abe

  AIAA-2013-1005  2013/01
• Validation of the Scale Effect for the Electrodynamic Interaction of a Magnetized Body in a Weakly-ionized Flow  [Not invited]

  Morimasa Hattori, Aseu Tezuka, Hitoshi Makino, Yasunori Nagata, Yusuke Takahashi, Takashi Abe

  AIAA-2012-2738  2012/06
• Radio Frequency Blackout Possibility for an Inflatable Reentry Vehicle  [Not invited]

  Yusuke Takahashi, Kazuhiko Yamada, Takashi Abe

  AIAA-2012-3110  2012/06
• Nonequilibrium Plasma Flow Properties in Arc-Heated Wind Tunnels  [Not invited]

  Yusuke Takahashi, Takashi Abe, Hiroki Takayanagi, Masahito Mizuno, Hisashi Kihara, Ken-ichi Abe

  AIAA-2012-1240  2012/01
• Numerical Study of Pyrolysis Gas Flow and Heat Transfer inside an Ablator  [Not invited]

  Naoya Hirata, Sohei Nozawa, Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  the Asian Symposium on Computational Heat Transfer and Fluid Flow  2011/09
• Numerical Simulation of Flow Field and Heat Transfer around HAYABUSA Reentry Capsule  [Not invited]

  Masataka Yamada, Yohei Matsuda, Naoya Hirata, Sohei Nozawa, Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  the 28th International Symposium on Space Technology and Science  2011/06
• Numerical Simulation of Flow Fields in Large-Scale Segmented-Type Arc Heaters  [Not invited]

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  27th Congress of the International Council of the Aeronautical Sciences  2010/09
• Numerical Investigation of Thermal Response of Ablator Exposed to Thermochemical Nonequilibrium Flow’  [Not invited]

  Tadashi Kanzaka, Sohey Nozawa, Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  The 6th Asian-Pacific Conference on Aerospace Technology and Science  2009/11
• Numerical Investigation of Thermochemical Nonequilibrium Flow Field in a 20kW Arc Heater Coupled with Electric Field Calculation  [Not invited]

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  26th International Symposium on Rarefied Gas Dynamics  2008/07
• Numerical Simulation of Plasma Flows in a 20kW Arc-Heated Wind Tunnel Using Multi-Temperature Model  [Not invited]

  Yusuke Takahashi, Hisashi Kihara, Ken-ichi Abe

  Third Asian-Pacific Congress on Computational Mechanics in conjunction with Eleventh International Conference on Enhancement and Promotion of Computational Methods in Engineering and Science (APCOM’07-EPMESC XI)  2007/12

Teaching Experience

Computational Fluids MechanicsComputational Fluids Mechanics Hokkaido University
Advanced Fluid EngineeringAdvanced Fluid Engineering Hokkaido University
Introduction to Flight DynamicsIntroduction to Flight Dynamics Hokkaido University
Scientific mission and design of reentry spacecraftScientific mission and design of reentry spacecraft Hokkaido University

Research Projects

• Research on Advanced Applications of Deployable Aeroshell Technology to Realize Ultra-Small Planetary Probes

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2020/04 -2023/03 

  Author : 山田 和彦, 永田 靖典, 高橋 裕介, 佐藤 泰貴

   

  本研究課題は、新しい大気圏突入技術として注目されている展開型柔軟エアロシェル技術をさらに進化させて、新たな応用範囲を切り開くことを目的としている。特に、１）大気圏突入中に展開エアロシェルを切り離すことで、探査機を惑星周回軌道投入を実現できる抗力変調型のエアロキャプチャ技術と、２）超軽量で、シンプルかつロバストな展開型エアロシェルが実現できる可能性があるSMA（形状記憶合金）型の展開エアロシェル技術に取り組んでいる。 2021年度の最も重要な成果は2021年12月に実施した極超音速風洞試験である。上記の1),2)の両テーマともに、2020年度に実施した極超音速風洞試験の結果を踏まえて改良した模型や試験システムを用いて、JAXA調布のΦ1.27m極超音速風洞にて風洞試験を実施した。1)の抗力変調型のエアロキャプチャに関しては、６分力測定、及び、画像計測系を改善し、エアロシェル分離時の挙動をより詳細に測定することに成功した。また、エアロシェルサイズを変更した実験を行い、2020年度の成果と併せて、エアロシェル形状の影響についても知見を取得できた。2)のSMA型エアロシェルについては、2020年度の試験時の課題であったフラッタ現象は、模型を改良することで回避でき、極超音速気流中での空力加熱によるSMA型エアロシェルの完全受動展開実験に成功した。展開中の流れ場の可視化、６分力測定、温度履歴の測定を実施し、模型形状と展開挙動の関係や空力特性を取得することができた。 それと平行して、抗力変調型エアロキャプチャに関しては、火星以外の天体（金星）への適用について、軌道解析による評価を行った。また、FSI(Fluid-structure Interaction)解析による柔軟エアロシェルと高速流体の連成解析ツールの構築も進め、これらの現象をより深く理解するための準備を整えた。
• Evaluation of Aortic Dissections and Treatment Methods using Numerical Simulation

  Research Organization for Information Science and Technology：FY 2022 Joint Usage/Research Center for Interdisciplinary Large-scale Information Infrastructures (JHPCN)

  Date (from‐to) : 2022/04 -2023/03 

  Author : 武田量, 佐々木克彦, 大島伸行, 横山博一, 黒田明慈, 柴田良一, 高橋裕介, 髙嶋英厳, 李辰宇
• 大型プラズマ風洞を用いた再突入ブラックアウト低減化研究の深化と加速

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2018 -2022 

  Author : 高橋 裕介

   

  大気再突入時に高温プラズマに包まれた宇宙機が、地上局やデータ中継衛星との通信途絶現象（通信ブラックアウト）に陥ることがある。通信ブラックアウト低減化は着地着水点の高精度予測や再突入中のデータ送受信の上で重要な課題である。これまで磁場印加や、柔軟構造再突入機、テラヘルツ波など様々な低減化手法が提案されている。いま課題実施者の研究グループでは、表面触媒性を用いた宇宙機後流プラズマ密度低下を利用することによる新しい通信ブラックアウト低減を提案している。ここでは表面効果による通信ブラックアウト低減化メカニズムおよび低減化技術の指針を見出すことを目的とする。 再突入機近傍のプラズマ諸量分布や電磁波挙動の正確な予測が難しく、通信ブラックアウト低減に繋がる知見の探索が困難な状況であった。この問題を緩和するために、再突入時における宇宙機近傍の電磁波挙動を明らかにすることは有効である。本課題実施者は、これまでプラズマ流解析・電磁波解析ソフトウェアを開発し、再突入時における宇宙機近傍の電磁波解析を明らかにしてきた。ここではそれをコア技術として、大型風洞による低減化実証と合わせて研究を推進する。 昨年度に引き続き本年度でもドイツ航空宇宙センター（DLR）に滞在し通信ブラックアウト低減化研究を実施する予定だったが、新型コロナウイルス感染症拡大防止方策に伴う海外移動制限から今年度も残念ながら断念した。一方でDLR研究者との議論は継続しつつ、現所属機関（北海道大学）において遂行可能な低減化研究の実施を行った。それはJAXAプラズマ風洞における実証試験とスーパーコンピューター富岳などを用いた大規模数値計算である。主にはこれら２つのアプローチを用いて従来課題の低減化手法の研究を行うとともに、新しい低減化技術の実験的・数値的実証も実施した。
• Study on Reduction of Reentry Blackout by Surface Catalysis Effect

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2017/04 -2020/03 

  Author : Takahashi Yusuke

   

  The radio frequency (RF) blackout for telecommunications between a reentry vehicle and a ground station hinders the accurate prediction of landing sites and increases the recovery cost. A mitigation method of RF blackout has been demanded. In this study, I proposed and demonstrated the new mitigation method using the surface catalysis effects with numerical simulation approach and wind tunnel experiments. The communication situation in reentry plasma was experimentally reproduced by 1 MW arc-heated wind tunnel, which generates high-temperature flows on the ground. Comparative tests were performed by two test models with high and low catalysis material of surfaces. The results indicated that the test model having high catalysis improves the communication situation, that is, mitigation of RF blackout. In addition, the mechanism to mitigating the RF blackout was clarified by the use of numerical analysis.
• Study on behavior of a spacecraft with membrane aeroshell in super low earth orbit and flight demonstration using a nanosatellite.

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2015/04 -2018/03 

  Author : YAMADA Kazuhiko, SUZUKI Kojiro, IMAMURA Osamu, AKITA Daisuke, ISHIMURA Kosei, NAKASHINO Kyoichi

   

  In this study, the behavior of a spacecraft with low-mass and large membrane aeroshell in super low earth orbit is measured in real flight using the nanosatellite EGG. The group of attitude sensors including inertial sensor, optical sensor and faraday cup sensors which can be installed in nanosatellite EGG was developed. In EGG’s flight operation, we acquired a lot of valuable flight data related to attitude motion and orbit change of a spacecraft with a membrane aeroshell. For example, an orbit change history of EGG by the aerodynamic force acting on the membrane aeroshell in rarefied flow was observed continually. These flight data are expected to be useful for the development of an important technology for nano-satellite, that is, an orbit collapse technology to prevent from becoming space debris.
• A Study on Radio Frequency Blackout of Planetary Atmospheric Reentry Vehicle

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2014/04 -2016/03 

  Author : Takahashi Yusuke

   

  An analysis model of plasma flow and electromagnetic waves around a reentry vehicle for radio frequency blackout prediction was developed. The plasma flow properties in the shock layer and wake region were obtained using a newly developed unstructured grid solver that incorporated real gas effect models and could treat thermochemically nonequilibrium flow. To predict the electromagnetic waves in plasma layer, a frequency-dependent finite-difference time-domain method was used. The combined model was validated based on experimental results in atmospheric reentry missions. The prediction performance of the combined model was evaluated with profiles and peak values of the electron number density. The signal losses measured during communication were directly compared with the predicted results. Based on the study, it is suggested that the analysis model could be an effective tool for investigating radio frequency blackout and plasma attenuation in radio wave communication.
• A study of plasma flow field around dielectric barrier discharge plasma actuator for high velocity flow condition

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2011 -2012 

  Author : TAKAHASHI Yusuke

   

  Final goal of the present research is to develop a high-performance plasma actuator which is applicable for a condition of high-velocity flow. In the present study, to describe plasma flow behavior and potential drop by cathode sheath, numerical simulation models of plasma flow generated by dielectric barrier discharge plasma actuator and plasma near an electrode has been suggested and developed.
• アーク加熱風洞を用いた高性能アブレータ開発に関する基礎研究

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2009 -2011 

  Author : 高橋 裕介

   

  本研究の目的を,再突入時の高温環境を模擬できるアーク加熱風洞を用いてアブレータ内部現象の定量的な調査を進めるとともに,軽量で耐熱性に優れるアブレータ材料とその形状モデルの指針を見出すことに設定し,本年度における研究を実施した.これまでの成果として,九州大学20kWアーク加熱風洞の加熱部における幅射熱輸送の役割について数値解析を用いて定量的に明らかにした.さらに,JAXA 750kWアーク加熱風洞や,NASA20 MW Aerodynamic Heating Facility,NASA60 MW Interaction Heating Facilityなど,多様な大型アーク加熱風洞に対して,加熱部における乱流・幅射熱輸送の挙動を数値的に調査し,その挙動を明らかにする成果を上げた.ただし,本解析モデルを用いた解析結果は,実験直に比べてアーク電圧を過少予測する傾向にあることがわかった.その理由のひとつとして,電極近傍におけるシースを考慮していなかったことが挙げられる.したがって,アーク加熱風洞の電極近傍におけるシースモデルを提案し,電圧降下及びアーク電圧の評価を行った. また,軽量アブレータが20kW及び750kWアーク加熱気流にさらされる条件下において,内部の熱分解ガス流動を考慮した内部熱応答解析モデルおよび周囲の高温気体との連成解析モデルの構築を行い,アブレータ熱応答解析モデルの高精度化を行った.解析結果と実験結果は良好な一致を示し,より高精度なアブレータ熱応答解析コードが開発された. 本研究を通して開発されたアーク加熱気流解析コード及びアブレータ熱応答解析コードによって,多様な風洞気流の諸量分布を提供することや,アブレータ内部の現象を定量的に調査することが可能になった.したがって,アーク加熱風洞を用いた様々な耐熱材料試験や開発を進める上で,これらは有効なツールになると考えられる.

Others

• 2021/04 -2021/04 Reviewer Awards (Plasma Science and Technology 2020)

  https://publishingsupport.iopscience.iop.org/questions/plasma-science-and-technology-2020-reviewer-awards/