A pressure-based composite grid method for the incompressible Navier-Stokes equations

In this work, a pressure-based composite grid method is developed for solving the incompressible Navier-Stokes equations on domains composed of an arbitrary number of overlain grid blocks, where a conservative internal boundary scheme is devised to ensure that global conservation is maintained. Issues concerning the differences between the conservative internal boundary scheme developed for the pressure correction method with a staggered grid and that commonly used for density-based methods for compressible flow with nonstaggered grids are discussed. An organizational scheme is developed in order to provide a general and more flexible means for handling arbitrarily overlain grid blocks. The data structures required, from a coding standpoint, for implementing the organizational scheme, and the design of the conservative internal boundary scheme within this framework are also presented. Applications of the composite grid method to various model problems with complex geometry are used to illustrate the characteristics of the present procedure.