G0601-3-3 Flow and Heat Transfer of Natural Convection around Horizontal Heated Square Cylinder

Abstract

Experimental investigation has been carried out on natural convection of water induced around heated, horizontal square cylinders. Main concerns were the flow and heat transfer characteristics of high-Rayleigh number flows. The flows around the square cylinder and the surface temperatures were visualized with dye and liquid crystal thermometry, respectively. The results showed that the ascending flows along the vertical side surface begin to separate three-dimensionally from the upper surface of the square cylinder when the modified Rayleigh numbers, Ra^*_d, exceed Ra^*_d =2×10^6. The local heat transfer coefficients were also measured. The results showed that the coefficients of the upper surface are increased, in particular, in the region behind the three-dimensional separation.