Development and validation of a full-interface numerical model for determining contact heat transfer coefficients at rough metallic interfaces

For the precise determination of the temperature distribution in technical systems using thermal modeling, the selected boundary conditions are crucial for the quality of the results. Especially at the contact surface between two components, thermal contact resistance plays a significant role in heat transfer within multicomponent systems. Although extensive experimental work has identified various factors influencing contact heat transfer, deriving universally applicable analytical models remains challenging due to the simplified assumptions made to represent complex surface geometries. In this work, a surface-resolved full-interface numerical model is presented to model the contact heat transfer coefficient between two contacting surfaces and their associated bodies. The numerical temperature profiles for three different sample pairings with varying surface structures are compared to experimental data from infrared thermography. A good agreement is observed for both the temperatures and the estimated contact heat transfer coefficients. The advantage of this surface-resolved approach is that it captures microscopic resistance due to roughness and macroscopic resistance due to long-wavelength form within a single integrated simulation, avoiding separate multiscale treatments and keeping computational effort acceptable. • Simulation of thermal contact heat transfer coefficients from surface scans. • Validation with experimental data shows good agreement. • Modeling the entire surface considering micro and macro resistance.