Author(s): Michael Tritthart; Dieter Gutknecht
Linked Author(s): Michael Tritthart
Keywords: 3D numerical modeling; Polyhedral cells; Validation; Finite Volume Method; Channel flow; River flow
Abstract: Typical three-dimensional CFD simulation software utilizes computation grids based on hexahedral, tetrahedral or wedge-shaped cells. Recently, Tritthart (2004) introduced a novel grid type which is based on a two-dimensional Voronoi decomposition and a vertical segmentation of the flow domain, resulting in generalized polyhedral cell shapes. A numerical model employing this technique to solve the Reynolds-averaged Navier-Stokes equations by means of the Finite Volume Method was developed. In this study, the numerical model was validated by simulating two test cases, a curved rectangular wind tunnel and a sharply curved laboratory flume, and comparing the results to experimental data sets. Cell shapes were varied so that the horizontal cell projection took quadrilateral and hexagonal shapes, respectively. While both configurations yielded results in accordance with the measured data, it was found that the grid based on hexagonal regions led to results which match the experimental data in near-wall zones more closely. Longitudinal and transversal velocity profiles for both validation cases, as well as water surface profiles for the sharply curved channel are presented and discussed in this paper.