Key words: Porous medium, heat generation/absorption.

Abstract: The present investigation deals with study of laminar natural convection flow with internal heat generation or absorption in porous enclosure. The numerical simulations were conducted using a numerical approach based on the finite volume method implemented in the code "Nasim". It is interesting to see that the internal heat generation numbers (RaI), Darcy number (Da) and porosity number (?), have a significant role in the heat transfer rate. For all values of the considered Da, the stream function maximum (?max) is found to increase as Da increases. On other hand, at higher value of (?=1), the transfer rate of the heat is so strong which causes a deviation of the heat source maximum temperature corresponding to the absorption case.