Numerical Simulation of Density Current Using Two-Phase Flow

Due to shear layer at the interface of density current and ambient fluid, density current disturbs and entrains the surrounding fluid. Most existing analytical and numerical models for density current flows are based on the equations for single-phase flows. In this research, the density current has been modeled with two-phase flow model. The governing equations are continuity, x- momentum, and y- momentum equations for every fluid. The volume-of-fluid (VOF) interface tracking technique which uses a piecewise-linear interface calculation (PLIC) in each cell is used to determine the deformation of free surface in density current, numerically. Surface tension is implemented by the continuous surface stress (CSS), and continuous surface force (CSF) methods. Finally, results of these two models are compared. The model has been verified with the experimental data sets. The Results show that the model can be applied to experimental cases and has acceptable level of accuracy.