A study of boiling heat transfer from a rotating horizontal cylinder

Abstract

The influence of rotation on nucleate boiling heat transfer from a horizontal heated circular cylinder rotating about its own axis in Refrigerant-113 and in distilled water has been investigated. Both copper and brass cylinders, 1.125 in. (2.86 cm) dia. and 8 in. (20.32 cm) long, were tested at heat flux densities between 8000 and 26000 Btu/hft 2 (25 200 and 82 000 W/m 2) for a range of rotating Reynolds numbers from zero to 2.6 × 10 5. It has been found that rotation has no significant effect on the heat-transfer coefficient for low to moderate speeds. In this region, for 0 ⩽ (Re = D 2ω 2ν ) < 0.35 [Re c = ( Nu sb 0.12(Pr) 1 3 ) 3 2 ] where Nu sb is the Nusselt number based on the cylinder diameter for stationary boiling, existing correlations of boiling heat transfer for a stationary surface for a specific liquid-solid interface could be used to predict the heat transfer rate. For very high rotary speeds boiling ceased and forced convection became the only mode of heat transfer. In this region, for Re > 1.35 Re c the experimental data are correlated well by Nu = 0.12 ( D 2ω 2ν ) 2 3 (pr) 1 3 Between these limiting cases, a smooth and gradual transition region was observed in which the size and the frequency of the bubbles decrease with increasing speed until the bubbles completely disappear. The heat transfer results for both stationary surface boiling and forced convection were found to be in general agreement with those of other investigators. In addition, the values of “ C sf ” and “ r” in the Rohsenow equation for boiling from a stationary cylinder for the brass-R-113 combination were determined.