A Sharp-Interface Immersed Boundary Method for Simulating Incompressible Flows with Arbitrarily Deforming Smooth Boundaries

We develop a sharp interface immersed boundary (IB) method to simulate the interactions between fluid flows and deformable moving bodies. Fluid-solid interfaces are captured using a level-set (LS) function, which is updated at every time step by a reinitialization procedure. Motions of solid bodies are dynamically coupled with fluid flows by calculating the fluid forces exerted on solid bodies. The accuracy and robustness of the LS-based IB method are tested systematically in the context of several benchmark cases and self-propelled fish swimming. The effects of computational parameters on the accuracy of deformable body capturing are analyzed. It is found that the algorithm performs well in simulating the flow motions surrounding the deforming and moving bodies.