高温条件下接触热阻的数值模拟与试验研究

Numerical simulation and experimental investigation on thermal contact resistance at high temperature conditions

中文关键词: 高温  接触热阻  数值模拟  高温合金

英文关键词: high temperature  thermal contact resistance  numerical simulation  superalloy

中文摘要:

      接触热阻是衡量接触界面间传热效率的重要指标之一。利用ANSYS有限元软件对高温条件下高温合金GH4169界面间的接触热阻进行了研究。通过光学显微镜获得高温合金表面的真实形貌，并在ANSYS有限元软件中重建其表面模型，基于结构力学理论对接触界面微观结构的弹塑性变形进行模拟，以及传热学分析获得接触界面间的接触热阻值。研究了界面温度与接触压力对接触热阻的影响，同时考虑了高温条件下接触界面间辐射换热的影响，最后利用试验测试装置进行验证。结果表明：理论模拟与试验测试的结果两者之间的最大误差为12.6%，高温合金界面间的接触热阻随着界面温度和接触压力的增加而减小；接触界面温差随着界面温度的增加出现先增大后减小的趋势。

英文摘要:

      Thermal contact resistance is one of the important indicators to measure the heat transfer efficiency between contact interfaces. The thermal contact resistance between the interfaces of superalloy GH4169 at high temperature was investigated by ANSYS finite element software. The practical surface topography of the superalloy was obtained by optical microscopy, and the surface model was reconstructed in ANSYS finite element software. The elastoplastic deformation of the contact interfaces microstructure was simulat-ed based on the structural mechanics theory, and the heat transfer analysis was performed to obtain the thermal contact resistance. The effects of varying the interface temperature and contact pressure on the thermal contact resistance were investigated, with the consideration of the influence of radiation heat transfer between the contact interfaces at high temperature. Finally, the test device was used for verification. The results show that the maximum error between the theoretical simulation and the test results is 12.6%. The thermal contact resistance between the superalloy interfaces decreases with the increase of interface temperature and contact pressure; the temperature difference at the contact interface increases first and then decreases with the increase of interface temperature.