NEW. STRONGLY CONSERVATIVE FINITE-VOLUME FORMULATION FOR FLUID FLOWS IN IRREGULAR GEOMETRIES USING CONTRAVARIANT VELOCITY COMPONENTS: PART 1. THEORY

Abstract

A strongly conservative finite-volume procedure is presented for flows in complex geometries. The technique is based on a complete transformation of the governing equations, and physical velocity components, rather than the traditionally used Cartesian velocity components, are used as primitive variables. It was found that projecting the discretized vector transport equation in the direction of the covariant base vectors eliminated two substantial difficulties associated with flows in complex geometries. These difficulties stem from the presence of cross-pressure gradient terms and the need for a transformation between the different types of curvilinear velocity components in the mass conservation equation. It is shown that the present formulation ensures that the computational scheme is diagonally dominant. It was found that partially implicit treatment of nonorthogonal diffusion terms improved the convergence rate primarily for high-cell-Reynolds-number values. For nonstaggered grids, a new solution procedure that combines features of both the SIMPLER and PISO algorithms is proposed.

Notes

Address correspondence to D. L. Rhode, Department of Mechanical Engineering, Texas A & M University, College Station, TX 77843, USA.