Surface icing and phase change of water in hypersonic flow

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K18777
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 24:Aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: Toyota Technological Institute (2022-2023); The University of Tokyo (2021)
• Principal Investigator: Watanabe Yasumasa 豊田工業大学, 工学(系)研究科(研究院), 准教授 (60736461)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 極超音速 / 相変化 / 水 / 着氷

Outline of Final Research Achievements

Phase change of water and icing in hypersonic flow can affect aviation safety and aerodynamic characteristics of supersonic/hypersonic transport. Behavior of gas/liquid/solid water was measured in hypersonic wind tunnel tests and was characterized by experimental data. Unlike in subsonic aircrafts where icing tends to take place around leading edge of wings, ice layers were formed mostly near the trailing edge in hypersonic flow due to rapid change in flow temperature past expansion waves. Numerical simulation model for water droplet and air/vapor flow was proposed and its result showed a good agreement with findings in wind tunnel tests.

Free Research Field

航空宇宙工学

Academic Significance and Societal Importance of the Research Achievements

基礎化学的な水の非平衡相変化，物理学的な高速流体現象，そして壁面上の着氷現象という応用理工学が密接に関連した複合分野である極超音速機着氷現象に於いて，現象を定量的に観測しその特徴を解明し，着氷の形成しやすい条件の特定，簡易解析モデル構築により，水の高速気流との干渉現象を明らかにした事が学術的意義である．
水の相変化と高速気流干渉現象に対する解析手法により，水を素材・溶媒として用いる創薬・新材料開発分野に対しても，高速かつ柔軟な溶媒状態変化を利用した新たな材料合成手段への可能性を示す点で産業波及効果が期待でき，更に将来型航空機での着氷予測の基礎技術として安全安心な航行に資する点が社会的意義である．