An accurate conservative interpolation method for the mixed gridbased on the intersection of grid cells

A method is presented for conservatively transferring cell-centered physical quantities from one mesh to another with second-order accuracy, which is well-suited for finite-volume methods that rely on cell-centered variables. The proposed methodology implements the cell-intersection algorithm of 2D/3D mixed grid based on the local supermesh idea, and is able to accurately calculate the intersection of any two polygons or polyhedrons, thus providing a basis for accurate conservative interpolation. The accuracy and the efficacy of the new method are demonstrated with multiple 2D and 3D numerical experiments. The test results show that this method ensures strict conservation of physical quantities in the interpolation process, and achieves a higher accuracy than that achieved by conventional second-order interpolation methods.