Effects of contact-nature on transient thermal contact conductance

The behaviour of transient interfacial heat transfer across metallic contacts has significant importance in different heat transfer processes of practical importance, viz. casting, forging, smelting, soldering, glass forming etc. Present investigation systematically explores and develops an understanding of the effect of different nature of contacts on transient interfacial heat transfer/thermal contact conductance (TCC). In the present experimental investigation, six different contact configurations which represent conforming as well as non-conforming contacts of steel-steel have been selected towards estimating TCC under three consistent loading conditions. Sequential function estimation (SFE) algorithm utilizing single sensor data has been employed for solving related heat conduction problem (IHCP) using analytical solution for a semi-infinite body. Subsequently transient TCC is determined by the estimated transient average heat flux and instantaneous temperature jump. Results of transient TCC of different contact configurations show a definite effect of nature of contacts on transient TCC. This study suitably explains why different engineering applications show different behaviour of transient TCC under similar thermo-physical conditions. However, transient methodology which aims to determine the time varying estimate of contact heat transfer related with the specific application areas had seldom been used for estimating the steady state TCC. Further, in the present work, quasi-static thermal equilibrium obtained in transient test run, form the basis to successfully extract the steady-state TCC obtained by interfacial temperature drop, calculated without extrapolating the temperature profiles of each contacting body.