NUMERICAL-SOLUTION OF THE CONJUGATE HEAT-TRANSFER BETWEEN FORCED COUNTERFLOWING STREAMS

In this paper we study numerically the steady-state conjugate heat tra nsfer process between two counterflowing forced streams separated by a wall with finite thermal conductivity. Using the Lighthill approximat ion, the energy equations for both fluids can be written as an integra l relationship between the temperature and the temperature gradient at both interfaces. The energy equation for the solid given by the Lapla ce equation is solved numerically using the above mentioned boundary c onditions together with those coming from the adiabatic edges. Three n on-dimensional parameters appear in the problem, alpha, beta and epsil on. alpha corresponds to the ratio of the ability of the plate to carr y heat in the streamwise direction to the ability of the fluid to carr y out of the plate, beta ist the relationship between the thermal boun dary layer thicknesses of both fluids and epsilon corresponds to the a spect ratio of the plate. The distribution of the temperature of the p late as well the overall heat transfer rates have been numerically obt ained. The influence of the longitudinal heat conduction through the w all is very important on the overall heat transfer rates. The maximum average Nusselt number occurs for a finite value of alpha, depending s trongly on beta and epsilon.