Analysis of internal and external factors affecting thermal contact resistance from the perspective of entransy dissipation

Traditionally, the research on thermal contact resistance (TCR) is always believes that temperature boundaries affect TCR by affecting the thermal conductivity, ignoring its own significant influence. This study innovatively analyzes the formation mechanism and influencing rules of TCR from the perspective of entransy dissipation of theory. First, a TCR numerical model based on real rough surface morphology and experimentally validated is constructed. Then, the concepts of temperature gradient distribution non-uniformity (TGDN) and equivalent thermal conductivity (keff) are proposed, and the TGDN, keff and TCR of homogeneous thermal conductive materials under three types of temperature boundary conditions and non-uniform boundary temperature gradient distribution are analyzed. Finally, the TGDN, keff and TCR of heterogeneous thermal conductive materials under three types of temperature boundary conditions are analyzed. The results show that: the numerical TCR model has high accuracy, and the thermal conductivity and boundary temperature gradient distribution are internal and external factors affecting the TCR. keff is an effective evaluation standard for TCR of homogeneous and heterogeneous materials. In addition, TGDN, keff, and TCR results of the third-type temperature boundary condition is a perfect transition between the first and second types. This study lays a theoretical foundation for forming a perfect thermal solution.