A Noval Wave Estimator Based On The Central-upwind Scheme For Simulating Rapid Bed Erosion under Shallow Water Flows

Xin Liu, PhD candidate, Department of Civil Engineering, Ottawa, ON, Canada, Julio Ángel Infante Sedano, Assistant Professor, Department of Civil Engineering, Ottawa, ON, Canada and Abdolmajid Mohammadian, University of Ottawa, Department of Civil Engineering, Ottawa, ON, Canada

Contact First Author: Xin Liu; xliu111@uottawa.ca

Previously Published Material: The corresponding results are written in a paper submitted to the Journal of Hydraulic Research on 14 Jun 2014, and this paper is currently under review.

Abstract ID#: 34237

 

English Abstract:
A coupled numerical model with a novel wave estimator is developed to simulate the rapid bed-erosion under fast varying flows. To solve the hyperbolic governing bed-load sediment transport equation using a Godunov type Central-upwind scheme, a novel scheme estimating the numerical fluxes of bed-load terms using a different pair of bonding waves from hydrodynamic system is proposed. The two-dimensional shallow water equations are adopted to solve the hydrodynamic parameters. The morphology is updated by an Exner-based equation containing bed-load sediment transport as numerical flux terms. A general form of a bed-load transport formula with a complex definition of the bed-load coefficient is applied to calculate a universal solution of the eigenvalues of the Jacobian Matrix. The linear reconstruction of variables with a multi-dimensional slope limiter and the second-order Runge-Kutta scheme are employed to achieve higher accuracy in space and time. The proposed coupled model with novel wave estimator shows better stability and accuracy than the conventional decoupled models, which are verified by several numerical tests.
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