Heat transfer and entropy generation analysis of nanofluids flow in an open cavity

Mixed convection and entropy generation of nanofluids flow are numerically investigated in an open cavity heated from below with uniform temperature. Finite volume method was employed to solve the dimensionless governing equations of physical problems. The obtained results were presented by average Nusselt number, average entropy generation, Bejan number, streamlines and isotherms with various pertinent parameters, namely, Reynolds number (100 ⩽ Re ⩽ 500), Richardson number (0.05 ⩽ Ri ⩽ 1) and solid volume fraction of nanoparticles (0 ⩽ φ ⩽ 0.1), for three aspect ratios of the cavity (1, 1.5 and 2) and various types of nanoparticles (Cu, Al2O3, CuO and TiO2). It was found that the heat transfer and the entropy generation increase with the increase of Reynolds number, Richardson number and volume fraction of nanoparticles, and vary with the aspect ratio of the cavity and nanoparticle types. The choice of these parameters is important to obtain maximum enhancement of heat transfer with minimum entropy generation.