飞行器层板式前缘热管防热结构等效热分析

针对高超声速飞行器前缘尖锐部件所面临的严重气动热，提出层板式前缘热管防热结构。为避免前缘热管内复杂的两相传热传质计算，对高温热管蒸汽腔的传热进行了等效导热分析，讨论了蒸汽腔的等效导热系数的计算方法，与常规高温热管试验对比验证了计算方法的准确性。对该结构热防护效果的计算表明，当飞行器在34 km高度以7Ma速度飞行时，以IN718为管壁材料、Na为工质的层板式热管对头部半径为15 mm的前缘结构具有良好的热防护效果。
A new structure, the platelet heat pipe cooled leading edge, was proposed for hypersonic vehicle thermal protection. In order to avoid the challenge of modeling two-phase conjugate heat and mass transfer, an approach of modeling the vapor core as a solid thermal conductor with high conductivity was adopted and the effective vapor thermal conductivity was deduced mathematically. Its effectiveness was validated by comparing the wall temperature against experimental date for a conventional heat pipe. The research result indicates that the nickel based alloy IN718, with sodium as the working fluid, is a feasible combination form Mach 7 with a 15 mm leading edge radius.