Author(s): Akihiko Nakayama
Linked Author(s): Akihiko Nakayama
Keywords: LES; River flow; Flood flow; River bend
Abstract: A large eddy simulation method that can be used to predict flood flows in natural rivers with varying discharge rates and the large movement of wetting front is presented. The method is constructed on the fixed rectangular grid identifying the position of the vertical position of the free surface in each grid that contains the free surface. The rest of the technique is similar to many other LES methods for flows in fixed fluid domain. One important difference is that the boundary condition on the bed is not applied on the velocity but the wall stress obtained from the wall-law is applied, so that the bed resistance is predicted well without resolving the viscous layer near the bed. Validation of the method in the collapsing water column and in curved channel is very good. Application to a real river is also reasonable.