NUMERICAL SIMULATION OF BACK STEP FLOW USING DENSITY FUNCTION METHOD WITH VERIFICATION OF MASS CONSERVATION

摘要

The density function method is one of the powerful tools for solving a complicated free surface flow problem. However, an air-water interface becomes dim due to a numerical diffusion and it leads conservation of fluid volume to failure. To avoid this problem the volume correction method has been developed. This method was verified to conserve the mass and volume of the fluid, so that this method is called the volume correction method with verification of mass conservation. However, it was verified for the closed boundary condition. In this paper, the volume correction method was applied to the open channel flow with the back step of which the boundaries are the open boundary conditions. It is found that the volume correction method is also effective to the open channel flow and the numerical results are almost in agreement with the experimental results.