Role of multiple discrete heaters on the entropy generation during natural convection in porous square and triangular enclosures

Comparative study based on the entropy generation analysis has been carried out within porous square and triangular (design 1 and 2) enclosures subjected to discrete heating involving double heaters (cases 1–3) and single heater (case 0) along each side wall during natural convection for Da m = 10 -5 - 10 -2 involving Pr m = 0.015 and 7.2 at Ra m = 10 6 . Galerkin finite element method is implemented for the accurate evaluation of the entropy generation terms involving thermal and velocity gradients based on elemental basis set. Cases 1–3 are found to correspond lower values of the entropy generation compared to case 0 especially at higher values of Da m .