Numerical prediction of high temperature thermal contact resistance of HTA-C/ZrB_2-SiC with radiation effects

摘要

High temperature thermal contact resistance is the research focus of many applications involving thermo-mechanical issues including spacecraft thermal protection, nuclear reactor cooling and heat treatment process. In this paper, a finite element contact model was developed with the rough surfaces, which were generated from the optically measured surface topography of HTA and C/ZrB_2-SiC. The mechanical deformation was conducted account for the elastic-plastic mechanics, then the thermal analysis was completed in terms of the interface heat transfer condition with the solid spots conduction, far-field and near-field radiation. The results show that thermal contact resistance decreases from 1611 to 488 mm~2K/W when the interface pressure increases from 0.1 to 0.6 MPa, as the solid spots conduction is sensitive to pressure. Also, thermal contact resistance decreases from 1611 to 340 mm~2K/W when the interface temperature increases from 630 to 1100 K, due to the enhancement of heat transfer by radiation. And the thermal contact resistance account for solid conduction and radiation is reduced to 1/25 of that only considering solid conduction. Additionally, the accuracy of present method was effectively validated by comparing the numerical results with experimental data.