飞行器热防护与利用一体化系统实验与模拟

Experiment and simulation on aircraft thermal protection and utilization integrated system

通过设计一种基于主动冷却的点阵桁架结构,在降低飞行器质量的同时,实现有效的热防护效果,并在该结构中加入半导体温差发电装置,将产生的气动热转化为电能,可用于飞行器小型用电设备供电。对该热防护与利用一体化系统进行了实验研究。在不同工况下,温差发电功率远大于主动冷却系统的泵功消耗,可实现主动冷却系统的自驱动。通过添加管内表面凸起和螺旋扭带扰流对翼前缘主动冷却点阵桁架结构热防护性能进行了优化研究。结果表明:管内凸起和扭带耦合时能明显改善系统的热防护性能,在流速为0.1 m/s情况下,以水为冷却工质时,外面板和内面板最高温度较光管情况下分别下降了14.4%、17.8%;以煤油为冷却工质时,两者分别下降了15.0%、34.5%。

When an aircraft flies at a high Mach number for a long time,the airflow in the boundary layer of the aircraft wall will generate aerodynamic heat because of strong friction,which can cause the temperature near the wall to rise or even exceed the temperature resistance limit of the material to the disadvantage of the aircraft.A lattice truss structure based on active cooling was designed to reduce the weight of the aircraft while achieving thermal protection effec⁃tively.At the same time,a semiconductor thermoelectric conversion device was added to the structure to convert the generated aerodynamic heat into electrical energy,which could be used to supply power for small electrical equipment of aircraft.The proposed integrated system of ther⁃mal protection and utilization was studied through experiment and the results showed that the power of thermoelectric conversion was much larger than the pump power consumption of the active cooling system,which can realize the self⁃driving of the active cooling system.Furthermore,the thermal protection performance of the actively cooled lattice truss structure was optimized by nu⁃merical simulation method,and the heat transfer effect was enhanced by adding the inner tube protrusions and the spiral twist.The results showed that the coupling of the inner tube protrusions and the twisted band can significantly improve the thermal protection performance of the system.At the flow velocity of 0.1 m/s,the maximum temperature of the outer and inner panels de⁃creased by 14.4%and 17.8%,respectively,when water was used as working fluid,and 15.0%and 34.5%,respectively,when kerosene was used as working fluid.