Two-Phase Flow Simulation of a Non-Boussinesq Density Current

Abstract

Boussinesq approximation was widely used in the previous studies to model dilute density or turbidity currents. This approximation was helping to simplify the governing equations and employing a single phase simulation of density currents. In contrast to the general approach of the previous researches who tried to avoid two-phase flow simulation, in this study the two-phase simulation of density current is performed to compare the solution based on the non-Boussinesq behaviour of the fluid with that assuming the Boussinesq approximation. The above goal has been achieved by employing the mixture model for the two-phase flow simulation. The geometry of study is based on a long shallow channel in which a high speed jet of salt-water entering the stilling fresh water via the sluice gate. Different turbulence models results have been compared with the experimental data in order to verify the best results. Also, results of two-phase simulation have been compared to those obtained by the Boussinesq approximation, results show that the two-phase simulation provides superior prediction compared to the conventional single phase flow simulation.