Numerical analysis of the effect of variable wall thickness on heat transfer for laminar flow between two parallel plates

Numerical Analysis of the Effect of Variable Wall Thickness on Heat Transfer for Laminar Flow between Two Parallel Plates A numerical analysis of heat transfer for laminar flow between two parallel plates channel has been performed. The numerical analysis has been carried out under hydrodynamically fully developed and thermally developing boundary conditions. It is assumed that on of the channel walls is perfectly insulated while the other wall has the finite thickness with constant surface temperature at the outer side. Heat conduction within the finite thickness wall is evaluated together with flow and heat convection of the fluid and then, the problem is considered as a conjugate heat transfer problem. An existing computer based two dimensional elliptic code has been modified for the defined problem. Wall profiles have been prescribed according to the variation of wall thickness as follows; negative slope, positive slope, optimum wall to minimize heat transfer from wall to flowing fluid and the constant thickness wall. The effect of the prescribed variable wall profiles on heat transfer characteristics was investigated and compared with the constant thickness wall. Numerical results show that the effect of variation of wall profile in lineer manner on heat transfer is not significant. On the other hand, the optimum wall profile which suggested by literature minimizes the heat gain of the fluid. Depending on Reynolds number, this fact becomes distinct with increasing wall thermal conductivity. Key Words: Conjugate heat transfer, Numerical analysis, Variable wall thickness