The Setup and Validation of a Numerical Model for Wall Shear in Trapezoidal Open Channels

Abstract

The validation of a numerical model is done using Computational Fluid Dynamics (CFD) commercial software ANSYS CFX. Six trapezoidal channels which were used by Tominaga et al. (1989) in their experimental studies are modelled. Special emphasis is done on the distribution of shear stress and secondary currents. The channels have the sidewall inclinations of 30o , 46o and 58o to the vertical. The bottom width of the trapezoidal channels is kept constant for each slant angle and only the depth is varied to get different aspect ratios. The roughness on the boundaries is also varied. The results are compared with the published results found in the literature. The results are quiet encouraging and the model may therefore be used with confidence for other similar studies.