探测器超高速进入火星过程的高温真实气体效应对飞行稳定性和防热系统影响极大,需要在初步设计阶段对探测器的气动力热特性进行精确预测.文章构建了采用流场直角与表面非结构混合网格以及网格自适应的直接模拟蒙特卡洛方法,模拟稀薄环境高温真实气体效应的依赖于温度的多原子分子振动激发和8组份54化学反应模型.通过计算"火星探路者"外形气动力系数随攻角的变化,并与文献提供的计算结果对比,有较好的一致性,验证了该文算法的可靠性.文章模拟了"火星科学实验室"在火星大气环境70km高度、进入速度为5.85km/s下的高温真实气体效应对气动力、气动热和流场特征的影响.通过与完全气体计算结果对比,表明高温真实气体效应影响下的激波脱体距离减小,表面热流降低,轴向力系数增加、配平攻角减小、压心位置随攻角变化显著.%The high temperature real gas effects have great impact on flight stability and thermal protection system during Mars exploration vehicles entry in the Martian atmosphere at hypersonic speed. The precise prediction on aerothermodynamic characteristics should be performed in preliminary design stage. The direct simulation Monte Carlo (DSMC) method is established on a hybrid structure of Cartesian coordinate mesh, surface unstructured triangular cell and adaptive grid procedure. Temperature dependence of polyatomic molecules vibrational excitement and eight species and fifty-four chemical reaction model are included to simulate real gas effects in rarefied environment. The computed Mars Pathfinder aerodynamic coefficient variations with angles of attack have good agreements with reference results to verify the reliability of present algorithm. The Mars Science Laboratory (MSL) aerothermodynamics are simulated in entry speed of 5.85 km/s at 70km altitude. The effects of high temperature real gas on aero-force, aero-thermal and flowfields are investigated. Compared with perfect gas model, the results show that real gas effects reduce the standoff distance of shock wave and surface heat flux, make axial coefficients increase, trim angle decrease and pressure center position vary significantly with angle of attack.
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