Effect of load application method on thermal contact resistance and uniformity of temperature distribution

Traditionally, the research on thermal contact resistance based on real rough surfaces is often limited to the uniform load. This study investigated the effects of the material, surface roughness, pressure load, and temperature on the thermal contact resistance and contact interface temperature distribution non-uniformity under a concentrated load. First, rough surfaces with different surface roughness degrees were generated by using a random generation method, and microscopic contact numerical models of three different materials were established. Then, the real contact area of different pressure loads under uniform and concentrated loads were calculated. Finally, heat transfer analysis was performed at different temperatures based on the microcontact state, the thermal contact resistance and the contact interface temperature distribution non-uniformity were calculated. Compared with the uniform load, the thermal contact resistance and the non-uniformity of the temperature distribution were improved under the concentrated load, and the effect was more obvious under the conditions of a large pressure load and small surface roughness degree. In addition, it was found that the uniformity of the temperature distribution on the contact surface was proportional to the real contact area and temperature instead of the thermal contact resistance except when the real contact area was very small.