降落伞-返回舱系统超声速自由降落及其控制的数值模拟和实验研究

The basic research of supersonic landing of parachute is an urgent need for aerospace science, especially for the deep space exploration, such as the Mars exploration. The opening, infaltion and steady falling process of parachute have been studied for a long time, but the mechanism of interactions of parachute with multi-physics process, when falling at supersonic speed is still not clear, particularly whether the breathing of parachute at supersonic free falling will cause the instability and dilaceration of canopy or not, which can cause the failure of the mission. Therefore in this project, these problems will be studied with numerical simulations and supersonic wind tunnel test. The technical difficulties includes the mechanics modeling of complicated cable and membrane structures, the lightweight and flexiblity of canopy, the air permeability of canopy, folding and contacting of canopy; unsteady fluid-structure coupling and complex interactions of shock waves, turbulence and boundary layer with parachute in the supersonic falling, and the numerical simulation and control of supersonic free falling of the system of parachute and re-entry capsule. All of these difficulties make the study of numerical simulation and supersonic wind tunnel test of supersonic free falling of the system of parachute and re-entry capsule to be one of the most challenging problems in aerodynamics.

对超声速降落伞进行基础理论研究是航空航天领域的迫切需求，具有普适性、前瞻性和实用性，特别是对于火星探测等深空探测领域，更具有基础支撑作用。人们对降落伞-返回舱系统的拉直、充气和稳定下降过程已进行了长期研究，但对其在火星大气条件下超声速降落伞与非定常激波等多物理相互作用过程和机理缺乏了解，特别是不知道在超声速降落时降落伞伞面的呼吸过程是否会导致伞面失稳、撕裂，因此本研究采用数值模拟和超声速风洞试验相结合的方法对上述问题进行研究。研究中将处理如下技术难点有：复杂索膜结构、伞衣轻质柔性、伞衣透气性、伞衣皱褶和接触等力学建模；非定常流固耦合以及超声速环境下的激波、湍流、边界层等复杂物理过程与降落伞结构的相互作用，以及降落伞-返回舱系统超声速自由降落的数值模拟及其控制等，所有这些难点使得超声速降落伞自由下降过程的精确数值模拟和超声速风洞试验研究成为空气动力学中最具挑战性的课题之一。

对超声速降落伞进行基础理论研究是航空航天领域的迫切需求，具有普适性、前瞻性和实用性，特别是对于火星探测等深空探测领域，更具有基础支撑作用。人们对降落伞-返回舱系统的拉直、充气和稳定下降过程已进行了长期研究，但对其在火星大气条件下超声速降落伞与非定常激波等多物理相互作用过程和机理缺乏了解，特别是不知道在超声速降落时降落伞伞面的呼吸过程是否会导致伞面失稳、撕裂，因此本研究采用数值模拟方法对上述问题进行研究。..发展了适用于降落伞柔性被动变形透气伞衣与非定常激波等多物理过程相互作用的物理机理研究的高精度、高分辨率并行数值模拟算法和软件包；研究了降落伞柔性被动变形透气伞衣与非定常激波等多物理过程流场数值模拟数据库和通过可压缩旋涡动力学理论流场分析对超声速降落伞-返回舱系统周围非定常激波与边界层、湍流、旋涡等多物理过程相互作用所揭示的物理机理；分析了超声速降落伞-返回舱系统自由降落及返回舱落点控制和姿态控制方法。