A coupling algorithm of the coupled level set and volume of fluid/immersed boundary method and adaptive mesh refine method for simulating multiphase flows

To handle multiphase (i.e., gas–liquid–solid) flow problems, an algorithm coupling the CLSVOF/IB (coupled level set and volume of fluid/immersed boundary) method with adaptive mesh refinement (AMR) for simulating multiphase flows is proposed in this paper. First, in order to accurately predict the gas–liquid interface, intermediate, re-distancing, and second reconstruction steps are incorporated are added. Second, the CLSVOF/IB method has been developed to handle the gas–liquid interface and the fluid (including gas phase and liquid phase)–solid interface. The direct forcing IB method is employed, which utilizes an artificial force at specific cells that contain both fluid and solid phases. Finally, in order to more accurately calculate the IB force term at the fluid–solid interface, an AMR-CLSVOF/IB coupling algorithm for simulating multiphase flow is developed, in which meshes near the gas–liquid interface and the fluid–solid interface are refined at each time step. The biggest advantage of this coupling way is that besides refining meshes at the gas–liquid interface for enhanced fluid detail capture, the meshes near the solid structure are also refined, so that the IB force cells can be used to effectively describe the actual solid boundary. By using the proposed AMR-CLSVOF/IB method, accurate simulations of dam-break flows impacting fixed structures are achieved, enabling detailed capture of water flow and splash breakup phenomena.