Mars has been one of the hot spots of human deep space exploration. Because of the presence of the atmosphere on Mars, the parachute has been an important deceleration device to ensure the safety of the Mars explorer landing on the surface of Mars. However, due to the density of the atmosphere on Mars is very thin, the mastery of parachute inflation performance in the Martian atmosphere environment is a key point to the descent and landing system of Mars explorer in the engineering design, and it is also a key point to establish the parachute-load system opening dynamic model in the Martian environment or numerical simulation system in order to evaluate the performance of the descent and landing system of Mars explorer. With using the parachute inflation model of axial-radial momentum conversation, the influence of atmosphere density on parachute inflation performance is studied, including parachute inflation time, inflation distance and canopy project area. The results show that some experiential formulas can not adapt to the Martian environment, the parachute inflation time and inflation distance increases rapidly with air density decrease in the Martian atmosphere; the variety of the canopy area during parachute inflation is a quartic polynomial with the inflation time. These research results are important and valuable for engineering design, test and evaluating performance of the descent and landing system of Mars explorer.%探测火星一直是人类深空探测的热点之一,火星上因存在大气层.降落伞一直是确保火星探测器安全着陆于火星表面的一种重要的气动减速装置.然而,由于火星上大气密度非常稀薄,因此掌握降落伞在火星大气环境下的充气性能是火星探测器着陆系统工程设计中的关键,同时也是火星探测器减速着陆系统工作性能评定的理论分析模型或数值仿真系统中必须要解决的一个问题.文章通过降落伞轴向-径向动量守恒充气模型,研究了大气密度对降落伞充气性能的影响,得到了大气密度对降落伞充气时间、充气距离、充气过程中伞衣面积变化的影响规律.研究结果表明,目前有关降落伞充气性能的一些经验关系式对于火星这种稀薄大气环境已不再适用;在火星稀薄的大气环境下,降落伞的充气时间、充气距离随大气密度的减小将急剧增大;伞衣阻力面积为充气过程中时间的4次多项式关系.该成果对于火星探测器减速着陆系统的工程设计、试验及性能评估等均具有较好的参考价值.
展开▼
