A predictive model for the thermal contact resistance at liquid–solid interfaces: Analytical developments and validation

Abstract

An analytical model has been developed to quantify and predict the Thermal Contact Resistance (TCR) at the liquid–solid interface. Contact topography and interface characteristics are included in the model through the inclusion of solid surface roughness parameters and the mean trapped air layer at the interface. In liquid–solid contact, air is often entrapped and compressed inside the microcavities of the solid surface roughness. The mean trapped air layer is determined from the mechanisms of contact at the liquid–solid interface. The proposed models determine the radius and the density of the microcontact points for a given set of contact conditions. The density and the radius of contact spots have been integrated into a classical thermal flux tube theory in order to calculate the TCR at a liquid–solid interface. The models have been applied to the casting–die interface in High Pressure Die Casting. The calculated TCR is found to agree with the experimentally determined results.