DETERMINATION OF THE INTERFACIAL HEAT-TRANSFER COEFFICIENT IN A METAL-METAL SYSTEM SOLVING THE INVERSE HEAT-CONDUCTION PROBLEM

Simulation of several industrial processes involving solidification of metals requires characterization of heat transfer coefficient at the solidifying metal/metal-substrate interface. In the present investigat ion an attempt has been made to estimate this heat transfer coefficien t, h(c), using simulated experiments in which the heat transfer from a heated stainless steel block (simulating solidifying metal) to a wate r cooled copper block (simulating metal-substrate) is monitored by con tinuously recording temperatures at a few internal locations both with in the metal black and the substrate block. The problem of determining the interfacial heat transfer coefficient is recognized to be an inve rse heat conduction problem (IHCP). A numerical method is employed to solve IHCP and to determine the h(c) from the transient history of tem peratures at a few locations. The effect of the physical nature of the interface,as well as the cooling conditions prevailing at the outer s urface of the substrate on h(c) is examined and discussed. While the p hysical nature of the interface, i.e. roughness on the metal as well a s the substrate surfaces, has a significant effect on h(c), the coolin g conditions have only a marginal effect. The h(c) in the present inve stigation remains more or less time invariant.