MIXED CONVECTION FLOW AND HEAT TRANSFER IN A VENTILATED INCLINED CAVITY CONTAINING HOT OBSTACLES SUBJECTED TO A NANOFLUID

Abstract

The present study focuses on the problem of mixed convection fl uid fl ow and heat transfer of nanofl uid in a ventilated square cavity. The cavity contains two heated blocks subjected to external Al2O3–water (with particle diameter of 47 nm)nanofl uid, while temperature and nanoparticle concentration are dependent on thermal conductivity and eff ective viscosity insidea square cavity. The governing equations have been solved utilizing the fi nite volume method,while the SIMPLER algorithm is used to couple velocity and pressure fi elds. The natural convection eff ect is obtained by heating from the blocks on the bott om wall and cooling from the inlet fl ow. Using the developed code, the eff ect of Richardson number, the aspect ratio of hot blocks, solid volume fraction, and cavity inclination angles on the thermal behavior and fl uid fl ow inside the cavity are studied. The study has been executed for the Richardson number in the range of 0.1 ≤ Ri ≤ 10, solid volume fraction 0 ≤ φ ≤ 0.06, aspect ratio 0.5 ≤ AR ≤ 1, and cavity inclination angles between 0° and 90°.The obtained results are presented in the form of streamline and isotherm counter and Nusselt diagrams. It was observed from the results that for both obstacles and in all ranges of the parameters in this study, adding nanoparticles to the base fl uid or increasing the volume fraction of the nanoparticles causes the Nusselt number increases. Also, the rate of heat transfer increases when the Reynolds number increases.