An Experimental Study of Low Prandtl Number Natural Convection in an Array of Uniformly Heated Vertical Cylinders

Abstract

An experimental program was conducted to study natural convection heat transfer in an array of uniformly heated vertical cylinders in mercury. The cylinders were arranged in an equilateral triangular pattern, and three bundle spacings, P/D = 1.5, 1.3, and 1.1, were studied. The heat transfer results are presented as local Nusselt number—modified Grashof number correlations. The results indicate a strong dependence on cylinder spacing and the somewhat lesser effects of heat flux and circumferential position. In addition, mean radial temperature profiles were recorded for various conditions as well as the fluctuations in the fluid temperatures which were encountered. The influence of cylinder spacing and axial, radial, and circumferential position on these profiles and disturbances is discussed.