Experiments on pool-boiling heat transfer

Abstract The characteristic pool-boiling curve was measured for n-pentane at atmospheric pressure as a function of surface roughness, material and cleanliness. The maximum nucleate-boiling heat flux and the film-boiling curve were independent of surface conditions. The nucleate-boiling heattransfer coefficient varied by 600 per cent owing to variations in surface finish. It was concluded that transition boiling is a combination of unstable nucleate and unstable film boiling alternating at any location on the heating surface. The transition-boiling heat-transfer data plotted as log (q/A) vs. log (ΔT) was found to be correlated by a straight line connecting the maximum and minimum heat flux points.