Modeling heat and mass transfer in laminar forced flow between parallel plates with suction or injection boundary conditions

A numerical model is developed to simulate the transport phenomena between parallel plates channel with one porous and one non-porous (or impermeable) wall. The continuity and momentum equations were solved first, assuming the wall Reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. The results show that at constant inlet and wall Reynolds number, the friction factor on porous wall with suction is bigger than that with injection, but the axial non-dimensional pressure drop with injection is larger than the pressure drop in fully developed flow between impermeable plates and also larger than the pressure drop with suction. This is because of the net increase of the mean velocity of flow along the channel when injection is imposed. In the presence of suction, the pressure drop is controlled by suction rate, and approached to a constant value as the inertia and viscous forces are counterbalanced in the flow. The energy equation is solved independently assuming constant suction rate of air in the porous wall using different thermal boundary conditions. The results show that the Nusselt number distribution along the channel depends on the thermal boundary conditions imposed on porous and non-porous walls. The thermal characteristics also depend on whether suction or injection occurs through the porous wall.