接触热阻对疏导式热防护结构防热效果的影响

 采用内置高温热管的疏导式热防护结构是一种新型高效的热防护方式,热管与高温复合材料之间的接触热阻(TCR)对防热效果有重大的影响。首先给出了一种疏导式热防护结构的计算模型,进而采用间接耦合的方法建立了由接触热阻引起的热力耦合问题的计算格式,在此基础上对不同预留间隙条件下的热防护结构进行了热力耦合分析,重点考察了接触热阻对其防热效果的影响。研究结果表明,采用预留装配间隙的方法可以有效降低结构的应力水平,但同时使得界面接触热阻增加,从而使得结构驻点温度升高,因此在采用预留间隙设计时必须在考虑界面接触热阻的条件下从结构强度和温度两方面对结构进行安全性评估。

Effect of Thermal Contact Resistance on the Performance of Heat-pipe-cooled Thermal Protection Structures

Heat-pipe-cooled leading edge structure is a novel and efficient thermal protection method,and the thermal contact resistance(TCR) between the heat pipe and high temperature composite material strongly influences the thermal protection performance of the whole structure.A computational model of the heat-pipe-cooled thermal protection structure is first constructed,and then the computational scheme of the thermomechanical coupling caused by thermal contact resistance is established based on the sequential coupling method.The thermomechanical coupling analysis of the thermal protection structure under different initial gaps are then performed based on the present method,with emphasis on the influence of thermal contact resistance on the thermal protection effect.Numerical results show that using the initial gap can greatly reduce the stress level of the structure,while the interface thermal contact resistance and stagnation temperature increase.In the structural safety evaluation of heat-pipe-cooled thermal protection structures,both the stress criterion and temperature criterion must be satisfied at the same time.