Author(s): Junqiang Xia; Binliang Lin; Roger A. Falconer; Guangqian Wang
Keywords: Morphodynamic model; Dam-break flows; Mobile bed; Coupled solution method; Finite volume method
Abstract: Dam-break flows usually propagate over mobile beds in alluvial rivers or channels where the processes of flow movement, sediment transport and morphological changes are interactive. However, the majority of existing 2D models used for simulating dam-break flows are only applicable to non-mobile or fixed beds. Details are given in this paper of the development of a 2D morphodynamic model for predicting dam-break flows over mobile beds. In this model, the 2D shallow turbid water equations, the non-equilibrium transport equations for graded sediments and the equation of bed evolution are used and solved simultaneously. The verified model is used to investigate the influence of different bed-material compositions on the hydrodynamics and the morphology of a channel bed caused by dam-break flows. Simulated results have indicated that it is necessary to adopt the governing equations in turbid water to simulate the morphodynamic processes caused by dam-break flows as the rate of bed evolution is comparable to changes in the flow.