Piv and numerical analysis of natural convective heat transfer and fluid flow in a square cavity with two vertical obstacles

Abstract

An experimental and numerical investigation of natural convection in a square cavity with two vertical baffles located on the bottom wall of the cavity was carried out in this paper. The cavity had top and bottom plexiglass walls and isothermal aluminum walls. Particle Image Velocimetry was the study's experimental method and Fluent 12.1.4 was the numerical software employed. Two dimensionless baffle heights, Hb=0.2 and Hb=0.4 were examined for Rayleigh numbers ranging from 104 to 105. The velocity maps and streamlines produced both experimentally and numerically were studied and analyzed. As the Rayleigh number increases, the velocity of the fluid inside the cavity increases. The streamlines show that for Hb=0.2 as the Rayleigh number increases, two vortexes form in the upper part of the cavity, while for Hb=0.4 the second vortex forms in the gap between the two baffles. The increase in dimensionless baffle height from 0.2 to 0.4 causes a substantial reduction in Nusselt number.