Thermal interaction between two vertical systems of free and forced convection

Conjugate heat transfer between two thermal systems of free and forced convection, separated by a vertical wall, is investigated theoretically. It is assumed that the heat conduction in the wall is only in the transversal direction. The situation considered is one in which the two vertical boundary layers of free and forced convection induced on wall sides are in counterflow. The study shows that the thermal interaction process between the two thermal systems is controlled by two dimensionless groups: The zeta parameter relates the heat transfer effectiveness of two convection layers, and omega parameter evaluates the wall thermal resistance to the forced-layer resistance. The obtained results explain the effects of these two parameters on the fluid-solid interfacial temperature at wall sides, the temperature fields in the solid and fluid regions, as well as the local and mean Nusselt numbers. Comparison is made between model predictions and numerical results obtained by FLUENT for special model problems.