Clarification on nonequilibrium thermochemistry around atmospheric entry vehicles using a ultra-fast imaging absorption spectroscopy

• Project/Area Number: 16K06890
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aerospace engineering
• Research Institution: Tokai University
• Principal Investigator: Yamada Gouji 東海大学, 工学部, 講師 (90588831)
• Co-Investigator(Kenkyū-buntansha): 川添 博光 鳥取大学, 工学研究科, 教授 (40260591)
• Project Period (FY): 2016-10-21 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2016: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 分光計測 / 再突入飛行 / 熱化学的非平衡 / 回転温度 / 振動温度 / 衝撃波 / プラズマ流 / Shock Wave / Spectroscopy / Nonequilibrium / Shock tube / Rotational temperature / Vibrational temperature / Shock wave / Rotational tempereture / VIbrational temperature / Spectrum fitting / Relaxation process / Absorption spectroscopy / Electronic state / 惑星大気突入 / 吸収分光 / 非平衡熱化学過程 / 高速プラズマ流

Outline of Final Research Achievements

In this study, characteristics of high temperature plasma flows around a space vehicle during entry flight were investigated using a ground testing facility called shock tube. Since high temperature plasma flows generated around a space vehicle emit strong radiation, emission spectroscopy has been conventionally applied to clarify characteristics of the flows. Information obtained by emission spectroscopy is limited. So, in this study, experimental investigation using absorption spectroscopy has been newly tried.

Academic Significance and Societal Importance of the Research Achievements

従来は、プラズマ流からの自発光計測より得られた情報により流れ場の特性が把握されてきた。しかしながら本手法では流れ場の断片的な情報しか把握できずに、宇宙機の熱空力特性の予測精度の不確かさが大きいという問題があった。これに対して本研究では、従来と異なる手法のアプローチにより流れ場の特性を調査するものであり、高温プラズマ流の物理的な解明や将来の高精度な宇宙機開発に貢献できると考えられる。

Research Products

• [Journal Article] Nonequilibrium Plasma Flows in a Mars Entry Flight condition (2019)
  • Author(s): 山田剛治、貝瀬航、梅澤昌史
  • Journal Title: AIP Conference Proceedings, 31st International Symposium on Rarefied Gas dynamics Volume: 印刷中
  • Peer Reviewed / Open Access
• [Presentation] Internal energy relaxation processes of nitrogen plasmas at different electronic states in an entry flight condition (2018)
  • Author(s): 山田剛治、梶野瑞基、川添博光
  • Organizer: 45th EPS Conference on Plasma Physics
  • Int'l Joint Research
• [Presentation] Influence of Electron Excitation State on Relaxation Phenomena of Nitrogen Molecules Behind Stronge Shock Wave (2018)
  • Author(s): 梶野瑞基、原田央、山田剛治
  • Organizer: 15th International Conference on Flow Dynamics
  • Int'l Joint Research
• [Presentation] Shock Tube Study of Nonequilibrium Plasma Flows in a Mars Entry Flight condition (2018)
  • Author(s): 山田剛治、貝瀬航、梅澤昌史
  • Organizer: 31st International Symposium on Rarefied Gas dynamics
  • Int'l Joint Research
• [Presentation] Analysis of the thermochemical process in the shock layer generating around space vehicles entering the Earth atmosphere (2017)
  • Author(s): 梶野瑞基、山田剛治
  • Organizer: Micro/Nano Technology Center International Symposium 2017
  • Int'l Joint Research
• [Presentation] Shock Layer Radiation Analysis for Spacecraft Reentry Flights (2017)
  • Author(s): 山田剛治
  • Organizer: Micro/Nano Technology Center International Symposium 2017
  • Int'l Joint Research
• [Presentation] Internal Energy Relaxation Process of Nitrogen Plasma in an Entry Flight (2017)
  • Author(s): 山田剛治、野内昌平、梶野瑞基
  • Organizer: The 2017 Asia-Pacific International Symposium on Aerospace Technology
  • Int'l Joint Research
• [Presentation] Thermochemical Process of Nonequilibrium Plasma Flows in a Mars ENtry Flight Condition (2017)
  • Author(s): 山田剛治、野内昌平
  • Organizer: 13th National Congress on Theoretical and Applied Mechanics
  • Int'l Joint Research