Abstract
IFEM (Immersed Finite Element Method) is an extended method from Immersed Boundary Method which is familiar as Finite Difference Method. In IFEM, the motion of structure is described as Lagrangian while that of fluid as Eulerian, and then the fluidstructure interaction force is added to the equations of motion for fluid using Dirac delta function. Therefore the reproduction of fluid meshes is not necessary. In the present paper, the conventional IFEM that is frequently utilized for fluid and flexible elastic structure interaction problems is applied to fluid-rigid bodies system by introducing the simple evaluation of internal force as zero and the reassignment of average velocity to rigid body.
