Experimental study of the turbulent free convection over horizontal smooth or grooved surfaces in an open cavity

Abstract

This study investigates the turbulent free convection in a tank of water with the bottom surface being a smooth or a grooved surface and the top of the water surface exposed to ambient. The experiments for smooth surface was done with four values of AR, 3, 2, 1 and 0.5, whereas for grooved surface, values of AR are 3, 2 and 1. Here AR is the aspect ratio (=width of fluid layer/height of fluid layer). Heat flux at the bottom surface was from electrical heating. Experiments have been carried out for modified Rayleigh number in the range of \(2.5 \times 10^{8}\le Ra\le 3 \times 10^{12}\). The experimental results indicate that AR has significant effect on heat transport and hence sensitive to the nature and structures of the large scale mean flows of the system.