A FAST-RUNNING SEMI-IMPLICIT NUMERICAL SCHEME FOR TRANSIENT TWO-PHASE FLOWS ON UNSTRUCTURED GRIDS

摘要

A numerical method is presented for transient two-phase flows on unstructured grids. The two-fluid, three-field model is adopted for two-phase flows. The solution algorithm is based on two existing semi-implicit methods and takes advantage of the two algorithms: The pressure correction is obtained from the momentum and continuity equations such that the pressure matrix becomes symmetric, allowing for faster convergence. At the same time, the energy and noncondensable gas quality changes are considered explicitly in the linearized continuity equations, resulting in accurate transient solutions. The results of verification show that the new method is faster and more accurate than the two earlier methods.