A MODELING OF A HORSESHOE VORTEX IN A DEPTH AVERAGED FLOW MODEL AND ITS VERIFICATION

Abstract

A depth averaged flow model is commonly used to simulate flows in rivers or lakes. However, it is not applicable to the case three-dimensional flow structures are predominant. To improve the model performance, several refined depth averaged models have been proposed, by incorporating the effects of secondary currents, flow acceleration/deceleration and vertical acceleration. Nevertheless, a horseshoe vortex in front of a bluff body cannot be reproduced in depth averaged flow model. In this study, a modeling of a horseshoe vortex is carried out theoretically, by including the effects of flow acceleration/deceleration and the development and attenuation of secondary currents. For verification of model, the proposed model is applied to the flows around a square cylinder and compared with the results of three-dimensional numerical simulation. The results showed that the present model can capture the fundamental features of horseshoe vortex.