Effects of turbulence models on forced convection subcooled boiling in vertical pipe

In this study, a two-fluid model coupled with wall boiling model was adopted to investigate two-phase forced convection subcooled boiling process in a vertical heated pipe based on FLUENT 14.5. The influences of turbulence models (k-ε models and k-w models) on flow and heat transfer in pipe were studied. The performances of different turbulent models, wall functions and two-phase turbulence treatments were analyzed based on four sets of grids by comparing the calculated results with Bartolemei experimental data. The results of k-ε models showed better agreement with experimental data than these of k-w models. The Dispersed and Per Phase treatments for two-phase turbulence parameters performed no better than the Mixture treatment. The enhanced wall function could not cope the situation for grid with near-wall Y-plus near to 1. k-ε models with appropriate mesh size performed excellent in predicting subcooled boiling in vertical channel. This work can be referred for choosing turbulence model when analyzing subcooled boiling by CFD methodology.