2021 Fiscal Year Final Research Report
Investigation of Magnetohydrodynamic Aerobraking from Super High Altitude by Ionization Ignition Method
| Project/Area Number |
19K22018
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 24:Aerospace engineering, marine and maritime engineering, and related fields
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| Research Institution | Tottori University (2021)
Yamaguchi University (2019-2020) |
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Principal Investigator |
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| Project Period (FY) |
2019-06-28 – 2022-03-31
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| Keywords | 大気圏突入 / 電磁力エアロブレーキング / レーザートムソン散乱法 / アーク風洞 / 膨張波管 / 空力加熱 / ホール効果 |
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| Outline of Final Research Achievements |
We investigated the existence and mechanism of the critical altitude in magnetohydrodynamic (MHD) aerobraking and obtained the following results. (1) We have conducted the laser Thomson scattering measurement around a magnetized body in the rarefied arc flow and captured the electron temperature increase by the Joule heating caused by the Hall effect, which is the cause of the critical altitude. (2) We developed a method of forcibly ionizing non-ionized high-enthalpy arc-heated airflow using an ionization seed. Using this method, we successfully made the shock layer ionized, and we observed the MHD shock layer enlargement from the self-emission change of the shock layer. (3) We tried to measure the MHD shock layer enlargement using an expanding wave tube flow that can faithfully reproduce the re-entry flow. Although we could not measure the effect in the experiment, we clarified the expansion tube flow conditions necessary for the shock layer enlargement using numerical analyses.
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| Free Research Field |
航空宇宙工学
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| Academic Significance and Societal Importance of the Research Achievements |
宇宙船が大気圏に突入する際、断熱材を用いて、過酷な空力加熱に耐える技術が使われている。本研究で取り組む電磁力エアロブレーキングは、再突入時に生じるプラズマを電磁力により制御し、能動的に加熱を避ける革新的な技術であり、宇宙船の再利用や安全性を格段に向上させる。本研究では特に、数値解析により予想された臨界高度（上層大気から突然大きな電磁力が発生する現象）の存在と物理機構を検証すべく、三種の高エンタルピー風洞を用いた実験と数値解析による検証を行った。臨界高度の実証はまだ道半ばであるが、臨界高度の原因となるジュール加熱を確認し、上層で強制的に電磁力を発動させる電離促進剤添加法の開発にも成功した。
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