热防护系统内形曲面的一种光顺算法

A smooth algorithm for endomorphic surfaces in thermal protection systems

摘要:

再入式运载器在返回大气层的过程中会遭遇严重的热流载荷，需要为运载器设计一套隔热瓦式热防护系统。由于运载器表面热流密度分布的差异，造成设计的热防护系统厚度出现阶跃，导致热防护系统的内形面不光顺，为此，提出一种内形面的光顺算法。该算法以热防护系统内形面型值点的位置为优化对象，对内形面进行光顺，根据处理后的内形面型值点坐标拟合出光顺的双三次B 样条曲面。结果表明：通过本文算法处理后的内形面每个节点的折拐角均降到10°以下，且重量比采用等厚度设计方法设计的热防护系统轻，解决了热防护系统的厚度阶跃问题，该方法是一种有效的光顺算法。

Abstract:

The re-entry vehicle will experience severe heat flow loads during its return to the atmosphere, requiring the design of an insulated tile-type thermal protection system for the vehicle. Due to the differences in the heat flow density distribution on the surface of the vehicle, a step in the thickness of the designed thermal protection system occurs, resulting in a poorly shaped internal surface of the thermal protection system, which is not smooth.The article proposes a smoothing algorithm for the endomorphic surface, which takes the position of the endomorphic surface type value points of the thermal protection system as the optimization object to smoothen the endomorphic surface, and fits the smoothened double-three times B-spline surface according to the coordinates of the processed endomorphic surface type value points, and the folding inflection angle of each node of the endomorphic surface is reduced to less than 10° which solves the thickness step problem of the thermal protection system, and the method is an effective smoothing algorithm.