Prediction of thermal contact conductance based on the statistics of the roughness profile characteristics

The roughness profiles of some common machined surfaces were measured. Four different criteria for determining contact peaks are presented. The distributions of the roughness profile height and the contact peak height were calculated. Based on the statistics of roughness profile characteristics, the thermal contact conductances for surfaces with different roughnesses were predicted. The results showed that the contact peak's criterion is crucial to the calculation of the distribution of the contact peak height. It has, however, limited influence on the prediction of thermal contact conductance. On the other hand, using several statistical roughness parameters or a single roughness profile is not adequate to describe the topography of the contact surface because of the contact surface's anisotropy. The values of predicted thermal contact conductance for surfaces with different roughness profiles form a steady prediction strip.