Numerical simulation of flow boiling in an orthogonally rotating duct

Abstract

Numerical predictions of flow boiling in a square tube rotating in vertical direction at a uniform rotating speed are presented. There-dimensional physical model and numerical model were established for simplified problem. Realizable k−e (RKE) turbulent model was employed to study vapor–liquid two-phase turbulent flow. Heat and mass transfer between vapor and liquid were solved based on volume of fluid multiphase flow model combined with user-defined function. The transient results show that wall superheat at onset of nucleate boiling (ONB) condition in rotating tube is obviously higher than that in stable tube. Based on Jens–Lottes formula of Bowring model, empirical formulas for wall superheat at ONB condition were modified with consideration of Rossby number. As the rotation speed increased, location of ONB shifts to the tube exit. Flow pattern in tube is determined by coupling effect of heating and rotation. Stability of flow pattern is gradually weakened during the increase in rotation speed. The numerical results are in fair agreement with two sets of experimental data for same physical model and working conditions.