THEORETICAL MODELING FOR PREDICTING THERMAL CONTACT CONDUCTANCE

Abstract

Many different analytical models have been developed over the last 40 years that take into account the different physical phenomena involved in contact heat transfer. Unfortunately, no universal model exists that can enable one to predict the thermal contact conductance between any two contact surfaces by measuring the real contact area using FEM software ANSYS. In this work, two methods of rough surface generation for different roughness values has .been developed by using rondam number generation using universal FEM software ANSYS. The resulting geometry is meshed by different meshing method to convert the solid model into FE model. The main aim of meshing in this model is to create a fine mesh at the contact and create coarse mesh at the remaining model to reduce the computational time. To create a fine mesh at contact free meshing with refinement and mapped mesh has been used. To create a contact pair between rough surfaces 8-noded surface to surface contact elements (CONTACT 174) and 3D target element (TARGET 170) are applied to the rough surface to create the contact and target surface and to allow 3D mechanical contact to occur and forces to be transmitted across the interface in the model. The analysis has been performed on the FE model with varying loading condition of different surface roughness and different materials to get the real contact area and thus thermal contact conductance. The variation of thermal contact conductance and real contact area with pressure of different surface roughness and with surface roughness of different loading condition of the specimen made of aluminum and mild steel has been plotted and compared