Estimation of thermal contact conductance using transient approach with inverse heat conduction problem

Abstract

Precise evaluation of thermal contact conductance (TCC) is essential for the thermal and mechanical analysis of a thermal system found in different engineering applications. Inverse heat conduction method provides an effective tool for the estimation of thermal contact conductance at the interface of two bodies in contact. In this work, 1-D inverse heat conduction method has been employed for the estimation of thermal contact conductance for metallic contacts. Function estimation technique using conjugate gradient method of minimization with adjoint problem has been utilized. Transient temperature data at fixed axial locations in the contacting bodies, their thermophysical properties and boundary conditions at the two ends are provided as the input to the inverse problem. Initially, the inverse method has been applied with the simulated data for various boundary conditions and different test functions to check the validity of inverse problem. Subsequently, the experiment has been performed for various boundary conditions, under different environmental, and loading conditions for metallic specimens. Transient temperature data from the experiments are provided as an input in the inverse problem. Eventually, the effectiveness and reliability of the transient approach based on inverse analysis has been established by comparing the results with their corresponding steady state values of TCC. The accuracy of the inverse solutions has been demonstrated with the help of parity plots. Conclusively, the transient approach has been found to be successful in TCC estimation with short duration experimental runs as compared to long waiting period of steady state TCC run. In addition, the transient approach eliminates the need for the measurement of heat flux and temperature drop at the interface, encountered in steady state approach.