Abstract
In this paper, the comparisons of the plane 2D flow model and the 3D flow model for the reproducibility of the local scour around a bridge pier is described. The river bed deformation model is the same in both flow models, and only the bed load is taken into consideration in this model. The FAVOR method and the collocated grid are applied in the 3D model, and the MacCormack scheme is applied to all models. The calculated results are compared about the initial flow, the shape of scour hole and the maximum scour hole depth. Moreover, the calculated maximum scour hole depth is compared with the field investigated results. From the comparisons of the calculated results, the 3D model can be reproducing the field investigated results rather than the plane 2D model, and the necessity of using the 3D model is pointed out for the prediction of local scour.
