Nonstaggered Calculation of Laminar and Turbulent Flows Using Curvilinear Nonorthogonal Coordinates

Abstract

A solution algorithm for the Navier-Stokes equations is tested by calculating laminar and turbulent flows over backward facing steps and laminar flow over obstacles. The solution algorithm is based on the finite volume method, curvilinear nonorthogonal coordinates, and a nonstaggered grid arrangement, and the connective fluxes are described by the power law scheme or the second-order upwind scheme. The Rhie and Chow interpolation method is selected for calculating the convective velocities on the cell faces to get good coupling between the velocity and pressure fields. When the flow is turbulent, the k-ε turbulence model with wall Junctions is employed. A highly deformed grid generated with an elliptic grid generator is used around the corners of the backward facing steps and obstacles; this represents a severe test of the algorithm. The results are compared with measurements and other calculations.