Fractal analysis of the thermal contact conductance for mechanical interface

•A method to estimate the fractal domain area is proposed.•A fractal model is proposed to predict the thermal contact conductance of mechanical interface with or without fluidic thermal interface material.•The experimental measurement of thermal contact conductance is conducted and validates the effectiveness of the theoretical analysis. As the increasing demand for thermal performance of mechanical products, thermal contact conductance (TCC) is widely used in the thermal-mechanical analysis. This paper presents a TCC prediction model based on fractal geometry. Besides the fractal dimension and fractal roughness parameter, the fractal domain area is estimated according to the fractal characteristics of the surface topography. Based on these three fractal parameters, the TCC of the interface with or without fluidic interface material can be calculated. The experimental results show that the fractal model is superior to the TCC models based on GW geometry in accuracy and numerical stability.