An improved hybrid Cartesian/immersed boundary method for fluid-solid flows

An improved hybrid Cartesian/immersed boundary method is proposed based on ghost point treatment. A second-order Taylor series expansion is used to evaluate the values at the ghost points, and an inverse distance weighting method to interpolate the values due to its properties of preserving local extrema and smooth reconstruction. The present method effectively eliminates numerical instabilities caused by matrix inversion and flexibly adopts the interpolation in the vicinity of the boundary. Some typical fluid-solid flows, including viscous flow past a circular cylinder, a sphere, two cylinders in a side-by-side arrangement, and an array of 18 staggered cylinders, are examined. These benchmark simulations reasonably indicate the reliability and capability of the present method. Copyright (C) 2007 John Wiley & Sons, Ltd.