关键词: 高超声速, 黑障, 等离子体流场, 化学反应模型, 电离反应, 灵敏度分析

Abstract:

During hypersonic atmospheric entry， vehicles encounter the “blackout” phenomenon， which severely affects communications. To accurately simulate the plasma flow field， it is essential to rely on accurate chemical reaction models. However， the applicability range of existing models has not been fully defined. This study employs sensitivity analysis to analyze the stagnation line flow field of the spherical nose in the flight corridor， aiming to evaluate five ionization reactions. The study finds that， in the altitude range of 58-64 km and Mach number range of 11-15， only the associative ionization reaction of nitrogen （N） and oxygen （O） atoms needs to be considered. In the altitude range of 64-70 km and Mach number range of 15-19， in addition to the associative ionization reaction of N and O atoms， the associative ionization reaction of O atoms must also be considered. Furthermore， in the altitude range of 64-70 km and Mach number range of 19-22， the associative ionization reaction between N atoms also become significant. Within the flight altitude range of 60-70 km and Mach number range of 22-26， it is necessary to consider the electron-impact ionization reactions of N and O atoms. Meanwhile， all ionization reactions should be taken into account. This study provides important theoretical basis and reference for the selection and application of chemical reaction models， contributing to improving the accuracy and reliability of plasma flow field simulation for re-entry vehicles.

Key words: hypersonic, blackout, plasma flow, chemical reaction model, ionization reaction, sensitivity analysis