I am working on the enhancement of heat transfer in oscillatory flow of liquid metals. The flow is between two parallel plates that are thermally conducting - finite thickness but infinite length. In the original article, the axial heat flux transported in the fluid is given by the product of thermal conductivity of the fluid, is the thermal gradient divided by the ratio of thickness of the plate to the channel width? Why do we divide the usual flux by the ratio of thickness of the plate to thickness of the channel width?
Is the original paper a numerical or experimental one ?
the general idea is to do energy balance at the wall surface that is heat being conducted through the wall = the heat conducted in the fluid in the very near wall (fluid have low motion there so convection can be neglected, and conduction is more important).