Sharp-Interface Cartesian Method for Simulating Flow past 3D Flexible Bodies

Abstract:- A second-order accurate, finite-difference numerical method is developed for solving the 3D, unsteady, incompressible Navier-Stokes equations in Cartesian domains containing geometrically complex, flexible, immersed boundaries. Unstructured, triangular meshes are employed to discretize complex immersed boundaries. The nodes of the surface mesh constitute a set of Lagrangian control points used to track the motion of the flexible body. The influence of the body on the flow is accounted for by applying boundary conditions at Cartesian grid nodes located in the exterior but in the immediate vicinity of the body by reconstructing the solution along the local normal to the body surface. The capabilities of the method are demonstrated by applying it to simulate flow past a swimming and maneuvering fish-like body. Key-Words:- Cartesian methods, immersed boundaries, fluid-structure interaction, aquatic locomotion