Numerical Simulation of Two-Phase Flows Using 3D-VOSET Method on Dynamically Adaptive Octree Grids

In this paper, a coupled volume-of-fluid and level set (VOSET) method is developed to simulate the two-phase flows. To improve the calculation accuracy of two-phase flows and reduce the cost of computer resources, the dynamically adaptive octree grids are used to refine the grids near the interface. For the deformation of a sphere, the numbers of cells and the CPU time are analyzed. The number of cells for the adaptive grid system is less than 550000. To keep the same resolution, the number of cells for the uniform grid system would be 4096000. The CPU time for the adaptive grids is less than 300 min, while it is 650 min for the uniform grids. The results demonstrate that using the adaptive octree grids takes less storage and time to achieve almost the same accuracy as employing the relevant uniform grids. A static drop in equilibrium without gravity is numerically simulated, and the results show that this method can accurately calculate the interfacial force. A rising gas bubble and the coalescence of two bubbles are simulated, and the results are in good agreement with the previous results.