Analysis of entropy generation during natural convection in discretely heated porous square and triangular enclosures

The present work involves the entropy generation studies within the porous square and triangular (models 1 and 2) cavities subjected to various discrete heating strategies at side walls (cases 1–4: symmetric heater locations, case 5: asymmetric heater locations) during natural convection over the wide range of Darcy number, Dam = 10−5 — 10−2, for various fluids (Prm = 0.015 and 7.2) at Ram = 106. Galerkin finite-element method has been used to solve the governing equations. The symmetric and asymmetric distributions of heaters have similar effects at lower Dam. However, the symmetric distribution of heaters corresponds to lower entropy generation rates at higher Dam. The triangular (model 1 and model 2) cavities are found to be optimal over the entire range of Dam (Dam = 10−5 — 10−2) based on the higher heat transfer rate and optimal entropy generation rates.