Axisymmetric simulation of bubble condensation of pure steam and steam-air mixture

A coupled compressive interface capturing scheme and dual-time preconditioned approach was developed for the two-dimensional axisymmetric computation of compressible interface flows with mass transfers. The fully-compressible three-phase homogeneous mixture flow model was implicitly solved using the dual-time preconditioned technique on generalized curvilinear grids. The interfaces between the three phases were captured by the solution of two interface advection equations using a compressive high resolution interface capturing method. The predictive capabilities of the numerical scheme were examined for a series of bubble condensations of pure steam and steam-air mixtures in different thermal and hydrodynamic subcooled boiling flows. Reasonably good agreement with the experimental data was obtained. Subsequently, several test cases on the condensation of single steam-air mixture bubbles were performed to investigate the effects of non-condensable gases on the characteristics of a condensing bubble. The numerical results revealed a nearly linear decrease of the condensation rate with an increase of the non-condensable gas void fraction in the mixture bubble.