Evaluation of three-dimensional overlapping grids and multigrid methods for calculation of flows.

Authors: Tu, J.Y., Fuchs, L.F.
Document Type: Article
Pubstate: Published
Journal: J. Num. Meth. In Eng.
Year: 1994


A computational methodology combining overlapping grid techniques with multigrid methods has been developed for three-dimensional flow calculations in or around complex geometries. The computational accuracy, efficiency and capability of the present approach are investigated in this paper. The incompressible Navier-Stokes equations are discretized using a finite volume method on a semi-staggered grid. The discrete problem is solved by a multigrid algorithm. Some numerical examples are chosen for evaluating numerical accuracy: (a) a straight pipe for which the exact solution is known; (b) curved pipes where previous experimental and numerical data are available; (c) an axisymmetric sudden expansion. The performance of the multigrid method on overlapping grids is assessed. Several cases of flows in stationary and time-dependent complex geometries are given to demonstrate the capability and the potential of the methods that we employ.