Reordering of Hybrid Unstructured Grids for Lower-Upper Symmetric Gauss-Seidel Computations

This note is devoted to the three-dimensional hybrid grid implementation of the LU-SGS method. The original method was based on sweeps through grid node numbers and was applied to two-dimensional Euler computations. Unfortunately, in its original formulation, the method cannot be vectorized; in addition the method is not compatible with commonly used edge-based data structure. To fit the method to the three-dimensional computations on a vector supercomputer, grid reordering is necessary. It was applied to the cell-centered finite volume method