Modeling dam-break flows in channels with 90 degree bend using an alternating-direction implicit based curvilinear hydrodynamic solver

摘要

This paper presents a combined numerical and experimental investigation of dam break induced free-surface flows in channels with 90 degree bend. These types of flows are best described by the two-dimensional shallow water equations (SWE) representing the conservations of mass and horizontal momentums. In this study, the governing equations are solved numerically by means of an alternating-direction implicit (ADI) finite-difference scheme in a curvilinear coordinate and contravariant velocity system. This model is tested by simulating for various flow conditions including dam-break flows onto dry beds in a converging-diverging channel and a channel with 45 degree bend. Good fits of the present model predictions with published laboratory measurements are achieved. To further the validation of the model, a series of physical model tests for dam-break flows in a channel with 90 degree bend were conducted. The predicted time-varying water depths downstream of the dam face are shown to have a fairly good agreement with recorded data from model tests. The present ADI solver is found to be capable of capturing the formation and movement of steep wave fronts. (C) 2015 Elsevier Ltd. All rights reserved.