ENTROPY GENERATION DUE TO NATURAL CONVECTION COOLING OF A HORIZONTAL HEAT SOURCE MOUNTED INSIDE A SQUARE CAVITY FILLED WITH NANOFLUID

The objective of this paper is to investigate the natural convection cooling of a heat source mounted inside a square cavity with special attention being paid to entropy generation. The cavity is filled with copper-water nanofluid; the right vertical wall is kept at a constant temperature, while other walls are adiabatic ones. The numerical scheme is based on the finite volume method with the SIMPLE algorithm for pressure velocity coupling. In this study, the influence of some effective parameters such as the Rayleigh number, location of the heat source, and solid concentration are studied; then, entropy generation due to the heat transfer irreversibility and fluid friction irreversibility as a function of Ra and solid concentration and heat source location is studied. The result shows that location of the heat source is an important parameter affecting the flow pattern and temperature field and variation of the entropy generation. Consequently the optimum case is selected since the thermal system could have the least entropy generation and the best heat transfer rate.