空天飞行器热防护系统热短路与控制问题研究

Research on Thermal Short-circuit and Its Control in Thermal Protection System for Aerospace Vehicle

空天飞行器盖板式热防护系统(TPS)中存在支架热短路、缝隙辐射热短路问题。用有限元分析软件ABAQUS对这两种情形进行了热分析,结果表明,在再入段典型热载荷下,机体蒙皮各局部的最高温度值相差最大超过100K,机体蒙皮存在局部烧坏的危险。在热防护系统中加入了具有控制热流走向功能的散热片后,结果显示,支架热短路中蒙皮最高温度降低了90.18K,降幅达17.32%,板间缝隙底部最高温度降低了67.97K。在蒙皮局部烧坏危险点上方,散热片很好地控制了热流走向,使热量得到面内方向的分散,机体蒙皮温度分布更加均匀,局部烧坏问题得到了改善。

Thermal short-circuits at brackets and gaps between tiles always exist in the Thermal Protection System （TPS） for aerospace vehicle. Thermal analysis of these two cases is completed by using commercial FEM software ABAQUS. The results show that the difference among the highest temperatures in different locations on the vehicle body skin is over 100K, which would lead to a local bum out damage. After putting cooling fins into the TPS to control the heat transfer direction, new analysis results show that the highest temperature under the central post decreases by 90.18K and the falling range is 17.32%. The temperature at the bottom of the gap decreases by 67.97K. Cooling fins in TPS over the body skin can control the heat transfer directions effectively. This kind of control can make the heat disperse in the fin-plane and make the distribution of temperature of the body skin more uniform, which decreases the local bum out.