Entropy generation due to natural convection Couette flow of viscous incompressible fluids in a vertical parallel porous channel

Abstract

This work studies entropy generation and irreversibility distribution due to Couettte driven flow of a viscous incompressible fluid in a vertical channel formed by two parallel porous plates. One of the porous plates is stationary while fluid flow in the channel is induced by uniform motion of the other parallel porous plate. Isothermal heating of the moving plate and viscous dissipation cause heat transfer within the channel. The viscous dissipation is combined with natural convection, giving rise to non-linearity of the energy equation which is then coupled with the momentum equation. The coupling of the nonlinear energy equation with the momentum equation makes it practically not feasible to obtain a closed form solution to the problem, the homotopy perturbation method is therefore employed to obtain approximate analytical solutions to the formulated mathematical model capturing this physical phenomena. The approximate analytical solutions obtained for velocity and temperature are used to compute entropy distribution and irreversibility distribution. Effects of the governing parameters on velocity, temperature, entropy distribution and irreversibility are presented, studied and discussed with the aid of graphs. Results obtained from the present study reveal that there is higher entropy generation near the stationary cold porous wall than the moving hot wall. Systems with low Prandtl number tend to exhibit lower entropy generation number than those with higher Prandtl number.