一种半解析方法火星再入探测器一体化设计模型

A Semi-Analytical Integrated Model for Capsule Entering Mars Atmosphere

提出了一种火星再入探测器的半解析法一体化模型,为未来火星探测器的初步设计提供包括弹道、气动参数、防热系统在内的设计依据。在任务初步设计阶段,由于涉及多个学科,火星大气与地球大气模型差异很大,需要考虑的因素很多,因此需要一个半解析的,能够实时进行弹道、气动参数和防热层温度分布计算的设计工具。该工具应该包括气动外形、弹道、防热为一体的设计模型,且能满足计算负担要求。基于此,提出了一种普遍适应的火星探测器外形定义方程,并对其中的一种特殊情况进行了解析公式的推导。在合理假设的前提下,给出了计算防热层内部温度分布的半解析计算公式,并以MER-B(Mars Exploration Rover)探测器为例进行了弹道和气动受热仿真。计算结果表明,该一体化计算模型的仿真计算落点与实际落点很接近,达到了火星探测器初步设计阶段一体化的计算要求。

In this paper, an integrated model for capsule entering the Mars atmosphere is presented, in which the trajectory, heat transferring of TPS （thermal protective system）, and aerodynamics coefficients are semi-analytically calculated together. In preliminary design, because of the multi-disciplinary characteristics, it will take much time to get a result if the whole process is calculated totally with numerical models. In order to reduce the computational cost with reasonable accuracy, a semi-analytical model for calculating aerodynamic coefficients is developed. Furthermore, with a set of super-ellipse function defining the capsule geometry, an analytical model for calculating the TPS thickness is developed under the simplified conditions. All of them help reduce the computational cost and contribute to the preliminary mission design. Simulation results of reconstructing mission of MER-B （Mars Exploration Rover） show that the model works quite well. The data of trajectory and temperature are quite close to those obtained in the mission, and the computational cost is reduced while maintaining the accuracy at the same time.