Dam-break model with Characteristic-Based Operator-Splitting Finite Element Method

A finite element method, which is the characteristic-based operator-splitting (CBOS) algorithm, is adopted to solve unsteady incompressible Navier-Stokes (N-S) equations. In each time step, the equations are split into the diffusive part and the convective part. The convective part is discretized using the characteristic Galerkin method and solved explicitly. The moving interface is captured by the pseudo-concentration method, thus, a new dam-break model is established. Through the validation of a dam-break onto a downstream dry bed or wet bed, it is shown that the present model can accurately simulate the moving interface flows. We also study dam-break in a confined reservoir and the dam-break wave impact on a spur dike. The complexity of the interface shape occurring in the different stages, including the gradual formation of the air bubble in the case of dam-break in a confined reservoir, and the generation of dam-break wave, the overtopping the spur dike and the impacting on the downstream seabed in the case of the dam-break wave impact on a spur dike, can be obtained.