NUMERICAL INVESTIGATION ON THE INFLUENCE OF INTERSTITIAL FLUIDS ON THERMAL CONTACT CONDUCTANCE
In order to predict contact heat transfer, recent research has focused on developing a numerical tool, which models the mechanical behavior of the contact surfaces and calculates the resulting temperature field under heat load. To date, this method is based on the assumption, that transferred heat through contacting surfaces exclusively results from thermal conduction at the contacting spots, thereby disregarding heat flow through interstitial fluid within cavities of the contact region. This simplification is made, due to the low thermal conductivity of air. However, neglecting this heat transfer mechanism is inadmissible, if surface cavities contain certain liquids with higher thermal conductivity, which is a common occurrence in manufacturing processes. This contribution aims at developing a thermal model, which is able to account for the additional heat transfer through interstitial fluids. The methodology is presented in detail and dependencies of the contact heat transfer coefficient on interstitial fluids are shown. In addition, the model is validated against experiments conducted for different liquids with relevance to the machining process.