飞船返回舱气动热及烧蚀防热的不确定性初步研究

由于飞船返回舱的气动加热和热化学烧蚀是非常复杂的变化过程,许多参数很难测定,并且与材料制造工艺水平密切相关,目前使用的数据存在较大散布,需要研究这些不确定因素对防热效果的具体影响。本文数值模拟了炭化材料的烧蚀热响应过程,研究了气动加热及材料参数的不确定性对计算结果的影响,在对计算结果进行分析的基础上,定量地研究了这些不确定量对烧蚀防热影响大小,说明了防热材料的各物理量对烧蚀防热影响重要程度完全不同,应该对几个关键参数进行深入细致的研究。

STUDY ON UNCERTAINTY BANDS OF AERODYNAMICALLY HEATING RATE AND MATERIAL PERFORMANCE IN THERMAL PROTECTION FOR SPACESHIP CAPSULE

It is quite difficult to exactly measure the material performance and thermal-related parameters due to the complexity of aero-thermodynamically heating and thermo-chemical ablation for spaceship capsule. The capsule thermal-design methodologies are based on the measured data and correlations of simple theories to these data. Therefore, error margins for these data and theories will give rise to the uncertainties in thermal protection effects. In this paper thermal response and ablation of charring material is simulated numerically, and the influence of the uncertainty bands of aerodynamically heating rates and material performance in thermal protection prediction is studied qualitatively. The result indicates that not all the material performance can influence the uncertainty bands of thermal protection notably. Based on the analysis the major parameters that make contributions to these uncertainty bands are identified. The present work displays that the uncertainties in major parameters dominate the thermal uncertainty margins, and need to be investigated further in the future.