进入轨道偏差对火星科学实验室气动力特性的影响

针对火星科学实验室(MSL)高超声速进入过程,利用三维并行程序求解流体力学Navier-Stokes方程,耦合真实气体模型,分析火星大气中真实气体效应对进入器气动力特性的影响量在进入轨道发生偏差时的变化规律.结果表明:对海盗号的计算结果与飞行数据符合很好,验证了火星大气真实气体模型和计算方法;真实气体效应影响下,激波层厚度大为减小,温度下降明显,进入器阻力系数明显增加,升力系数变化不大,俯仰力矩系数增加,基准状态下配平攻角较完全气体减小约2.2°;高度不变,Ma数增加导致阻力系数和俯仰力矩系数增大,配平攻角和完全气体的差值由1.6°增加到2.6°,表明Ma数变大时真实气体效应引起的气动力变化增强;Ma数不变,高度增加略微减弱波后化学反应,对进入器气动力特性基本没有影响.

Impact of Trajectory Deviations on Aerodynamic Characteristics of Mars Science Laboratory

Three-dimensional Navier-Stokes equations in real gas models are solved with a parallel code to analyze aerodynamic characteristics of Mars Science Laboratory in hypersonic entry in Martian atmosphere. Good agreement between numerical results and flight data of Viking validates physical-chemical models and numerical methods. It shows that impacted by real gas effect,shock layer thickness is reduced; drag coefficient rises,lift coefficient is almost unchanged. Difference of trim angle between real gas and perfect gas is about 2.2°; As keeping altitude,greater Mach number results in greater drag and pitching moment coefficient. Difference of trim angle varies from 1.6° to 2.6°. Increasing Mach number enhances real gas effect. As keeping Mach number,increasing altitude weakens chemical reactions behind the shock,but it has weak influence on aerodynamic coefficient.