Finite element simulations on heat flow visualization and entropy generation during natural convection in inclined square cavities

Finite element based numerical simulation has been carried out for analysis of heat flow visualization and entropy generation during natural convection within inclined square cavities with hot wall (DA), cold wall (BC) and adiabatic walls (AB and CD). The numerical results are presented in terms of isotherms (θ), streamlines (ψ), heatlines (Π), entropy generation due to heat transfer irreversibility (Sθ) and fluid friction irreversibility (Sψ). Further, detailed discussion on variation of the total entropy generation (Stotal), average Bejan number (Beav) and average Nusselt number (Nu), with Rayleigh number (Ra) is also presented. It is found that, large heat transfer rate (NuDA) with less entropy generation (Stotal) occurs for φ = 15° cavities at convection dominant mode (Ra = 105) irrespective of Pr. Thus, inclined square cavities with φ = 15° may be used for all thermal processing operations involving various fluids (Pr = 0.025 and 998). © 2013 Published by Elsevier Ltd.