A detailed kinetic model for condensed phase reveals hypergolic mechanism of propellants for space crafts.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K14993
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 25020:Safety engineering-related
• Research Institution: Yokohama National University
• Principal Investigator: Izato Yu-ichiro 横浜国立大学, 大学院環境情報研究院, 准教授 (90794016)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 自着火反応 / 詳細反応モデル / 液相反応 / ヒドラジン / 四酸化二窒素

Outline of Final Research Achievements

The goal of this study is to establish a detailed reaction model for liquid-phase reactions and to understand the chemical mechanism of the auto-ignition phenomenon of N2H4/N2O4 propellants for spacecraft, which is a high-speed transient chemical reaction. We have established the world's first detailed liquid-phase chemical reaction mechanism of N2H4/N2O4 by utilizing the quantum chemical calculation/continuous dielectric model method (QM/PCM method) and achieved a theoretical analysis of the hypergolic reaction mechanism. The liquid-phase reaction of N2H4/N2O4 evolves in a completely different reaction path from the previously known reaction mechanism in the gas phase. The detailed reaction simulation succeeded in explaining the extremely short ignition delay time observed experimentally.

Free Research Field

安全工学

Academic Significance and Societal Importance of the Research Achievements

液相反応に関する詳細反応モデルは，当該ヒドラジン/四酸化二窒素系推進剤の自着火反応のみならずこれまでほとんど報告例がなく，世界に先駆けてこれを達成したことに学術的意義がある．深宇宙探査など我が国の宇宙基本計画に基づく今後の宇宙ミッション要求に応えるため，本研究で構築したモデルやメカニズムを活用することでN2H4/N2O4推進系スラスタのより安全かつロバストな設計(例えばハードスタート現象の解明や抑止など)を支援できる．