接触热导率数值预测研究

假设粗糙表面轮廓高度服从高斯分布,并将两粗糙表面间的接触等效为粗糙表面与光滑刚性表面的接触。由均方根粗糙度和平均凸峰坡度得出接触点的平均半径和单位面积内的接触点个数,分别建立了用圆柱体和圆锥台来表现接触粗糙峰的两种有限元模型,对接触热导率进行了数值预测。通过对比发现,用圆柱体来表现粗糙峰的模型计算出的结果与试验吻合较好,且其误差随界面载荷的增大而减小。

Numerically Predicting Thermal Contact Conductance

The distribution of roughness profile height is assumed to be Gaussian,and the contact between two rough surfaces is treated as that with an equally rough surface with an ideally flat plane.The mean radius of a contact point and the number of contact points in a unit area are deduced from mean surface roughness and mean asperity slope.Two types of finite element models are established to numerically predict the thermal contact conductance,which uses cylinder and truncated cone respectively to represent the asperity slopes.The contrast finds that the model which uses cylinder to represent asperity slopes agrees better with experiment results than the other model and that the error of the model that uses cylinder decreases with increasing interface pressure.