火星进入器高空稀薄气动特性

针对火星稀薄大气环境进入器气动特性问题,以类火星科学实验室外形为例,计算分析火星稀薄大气真实气体效应对气动特性的影响,给出火星高空稀薄环境下的气动特性规律。研究发现,随着飞行高度的增加,稀薄度增加,激波脱体距离、激波厚度增大,激波强度减弱,明显的激波结构逐渐消失,流场等值线更趋于圆弧状分布;真实气体效应使得迎风面压缩及背风面膨胀增强,轴向力、法向力及顶点力矩系数等预测结果与完全气体模型预测结果相比绝对值偏大;随着稀薄度增大,轴向力、法向力及顶点力矩系数等绝对值增大,在同样的迎角下,随稀薄度的增加,纵向压心前移,进入器的静稳定性变差。

Aerodynamics of Mars entry vehicles under hypersonic rarefied condition

Attempt has been made to analyze the aerodynamics of Mars entry vehicles under hypersonic rarefied conditions by simulating the flows around the Mars Science Laboratory.The effect of real gas model on hypersonic rarefied aerodynamics is investigated to obtain the aerodynamic characteristics of the entry capsule.The results show that as the flight altitude increases,rarefaction,shock standoff distance and shock thickness increases,shock intensity is weakened at the same time,and flow contours tend to be more of arc shape.Real gas effect results in compressibility of the windward and expansion of the leeward,and also increase of axial force coefficient,normal force coefficient and pitch moment coefficient.On the other hand,as rarefaction enhances,the axial force coefficient,normal force coefficient and pitch moment coefficient also increases.At the same angle of attack,the pressure center moves forward and static stability decreases as the flight altitude increases.