Application of WAF Method in Numerical Simulation of Roll Waves

مهندسی عمران فردوسی

Article 4, Volume 25, Issue 1, June 2014, Pages 43-58   

Document Type: پژوهشی

DOI: 10.22067/civil.v25i1.35796

Authors

A. Mahdavi^* ; N. Talebbeydokhti

Abstract

In this paper, the weighted average flux (WAF) method is used to investigate the development and propagation of roll waves in inclined steep channels. In fact, the WAF method improves the accuracy of the classic HLL scheme in evaluating numerical interface fluxes. The present shallow water solver is capable of efficiently capturing flow discontinuities associated with roll waves. In addition, it provides a robust approach to eliminate the numerical instabilities due to small water depths usually encountered in roll wave modeling. The simulated free surface profile and flow velocity show very satisfactory agreement with available analytical solution. The numerical results for time evolution of wave amplitude under different undisturbed Froude numbers are compared with those obtained by another numerical model. Comparisons are also made between water depth time histories computed by these two models. The observed agreement implies the efficiency and accuracy of the present scheme while it is relatively simpler in computer implementation and consumes shorter simulation run times.

Keywords

Nonlinear shallow water equations; roll wave; shock capturing scheme; weighted average flux

References