An algebraic elliptic grid generator with grid spacing control

Abstract

An Elliptic Multiblock grid generation technique is presented. Boundary orthogonality is imposed by floating the grid points along the boundary. A formulation is presented to maintain the grid spacing at the boundaries. For the case of three dimensions an improved search algorithm maintains the grid orthogonality on the surface along with grid spacing. The specification of orthogonal boundary condition as a natural outcome of grid generation process preserves the grid quality obtained by the standard elliptic solver. Grid clustering is done algebraically, thereby de-coupling it from the basic equation in the grid generation process. Elliptic smoothing is used to spread out the clustered grid points adaptively resulting in a very smooth, clustered grid. The advantage of floating grid points at the boundary is exploited to yield a customized clustered grid with smoother grid distribution. User interaction is aided with the help of a TCL (Tool Command Language) interpreter. Since the surface grid is generated along with the volume grid, the grid generation script can be readily reused to generate grids of similar topological structure. The features of grid generator has been demonstrated with typical examples.