基于多尺度迭代的低温结构界面接触热阻数值模拟方法

Numerical simulation method for interface thermal contact resistance of structure at low temperature based on multi-scale iteration

为了精确获得大型低温风洞内部结构的温度分布,研究了低温结构接触界面接触热阻的计算方法。根据低温结构接触表面的宏观表面形貌和微观表面形貌,分别构建了结构宏观尺度有限元模型和微观尺度有限元模型,其中前者为后者提供温差载荷和机械载荷,后者为前者提供接触热导,形成了基于多尺度迭代的接触热阻数值模拟方法。设计并加工了典型低温结构实例,基于多尺度迭代方法预示了该实例在低温真空环境下的接触热阻。基于稳态法搭建了接触热阻测量实验系统,施加了数值仿真环境下的温度载荷和机械载荷,测量了相应载荷工况下的接触热阻,实验结果表明数值仿真方法具有较高的预示精度。

In order to accurately obtain the temperature distribution of large cryogenic wind tunnel,the calculation method of the contact thermal resistance for contact interface of low-temper-ature structure was studied.According to the macroscopic surface morphology and microscopic surface morphology of the contact surface of the low-temperature structure,the macro-scale finite element model of the structure and the micro-scale finite element model were constructed respec-tively,in which the former provided the temperature difference load and mechanical load for the latter,while the latter provided the contact thermal conductivity for the former,and a numerical simulation method of the contact thermal resistance based on multi-scale iteration was formed.A typical example of low temperature structure was designed and machined,and the contact thermal resistance of the example in low temperature vacuum environment was predicted based on the multi-scale iterative method.Based on the steady-state method,a contact thermal resistance meas-urement experimental system was built,and the temperature load and mechanical load under the numerical simulation environment were applied to measure the contact thermal resistance.The ex-perimental results show that the numerical simulation method has high prediction accuracy.