An Improved Hybrid Cartesian/Immersed Boundary Method for Flow Simulation with Moving Boundaries

To simulate flow problems with moving fluid-solid interfaces, a boundary treatment technique based on a hybrid Cartesian/immersed boundary method is presented. In the vicinity of the immersed boundary, a forcing term is added into the governing flow equations to modify the discretization scheme for the viscous term during its spatial discretization. Addition of such a term enforces desired boundary condition on the immersed boundary. A one-dimensional linear interpolation scheme is used to obtained required information for the modified discretization scheme when dealing with a moving boundary. The present method is essentially second-order accurate and can obtain results that are in good agreement with benchmark references when simulating the flow induced by the in-line oscillation of a circular cylinder.