Solution of the boundary-layer equations for natural convection film boiling on vertical cylindrical surfaces

摘要

Film boiling around a cylinder has been studied with a pseudo-similarity method. The velocity, temperature profile, the heat and mass transfer performance and the vapor film thickness could be predicted by the model with the effects of thermal properties (Pr, vapor liquid pμ ratio, and cpv(T_w-T_(sat))/(h_(lv)Pr)) considered. The results show that the heat transfer performance of film boiling on a cylinder surface is much higher than that on a flat surface. The film temperature and the Nusselt number of the numerical model agree well with the experimental data from the literature within the tested ranges. The heat transfer rate and local heat flux of the pseudo-similarity method in this work are also compared with that of the perturbation method, the results from those two method are found a perfect match.