INVESTIGATION OF TRANSIENT INTERFACIAL HEAT TRANSFER ACROSS DIFFERENT CONTACTS OF MILD STEEL
Knowledge of transient behavior of interfacial heat transfer at the junction of metallic contacts is crucial in many engineering applications for their performance and safety. Existence of different natures of transient interfacial heat transfer across various types of contacts is seldom addressed. Moreover, transient methodology aims to determine the time varying estimate of contact heat transfer has not been explored previously in terms of extracting/representing the steady state thermal contact conductance (TCC) value from transient TCC curves. In the present study, three different geometric configurations, viz. flat-flat, cylinder-flat and cylinder-cylinder contacts of mild steel have been used in order to represent various types of contacts encountered in real engineering applications. A customized experimental setup has been used to conduct transient as well as steady state experiments for all three configurations under axial loading conditions. The study has been systematically explored towards estimation of transient TCC by solving related one dimensional inverse heat conduction problem (IHCP) using experimental data performed under three consistent loading conditions. Transient TCC is determined by estimated transient heat flux and transient temperature drop at the interface. Results of transient TCC of different configurations show a definite effect of types of contacts on the nature of transient TCC. Further, quasi-static thermal equilibrium achieved in the transient test run, forms the basis to successfully extract the steady-state TCC.