Immersed Boundary and Finite Element Methods Approach for Interaction of an Elastic Body and Fluid by Two-Stage Correction of Velocity and Pressure

A new method for solving fluid-structure interaction problem is proposed by coupling immersed boundary method (IBM) and finite element method (FEM). This new method enables efficient simulation of fluid-structure interaction. Pressure and viscous forces are used for fluid and elastic body coupling. Pressure field is solved using fractional step method (FSM). An efficient pressure retrieval method is developed to allocate pressure information from the nearest fluid cell to Lagrangian points on the object’s surface. At the cells occupied by solid region, velocity field is subjected to momentum exchange procedure. The second correction of pressure is undertaken in the occupied region. Simplified marker and cell (SMAC) method is used to find scalar values for velocity and pressure correction. The present method is applied to 2-D flow fields with an elastic body to show the applicability of the method. A NACA 0012 airfoil is used as the neutral shape of the elastic object within the flow. The airfoils are initially placed in a fluid at rest with attack angle of −5° and −10°. Then, a uniform flow is given at the inlet. The coupling of IBM and FEM to study fluid and elastic body interaction problem have shown promising results. The method also shows good performance in obtaining solution in a feasible computation time.