Analysis of pool boiling within smooth and grooved tubes

This work presents experimental data for R-113 pool boiling, at atmospheric pressure and moderate heat flux, inside vertical and horizontal aluminum open-ended tubes, whose internal surfaces are either smooth or grooved. The tube length is 40 mm and the internal diameters of the smooth and the grooved tubes are 16.64 and 15.88 mm, respectively. The results are presented and discussed in relation to the heat transfer coefficients and compared with the Cooper and the Forster and Zuber empirical correlations. For all the tests, the heat transfer coefficient of the grooved tube is higher than that of the smooth tube. For horizontal tubes, an elongated bubble at the top region promotes a butter local heat transfer coefficient as is indicated by the lower temperature than that of the bottom region, where the bubbles are isolated. (C) 2000 Elsevier Science Inc. All rights reserved.