A fully coupled numerical technique for 2D bed morphology calculations

Abstract

A fully coupled two-dimensional subcritical and/or supercritical, viscous, free-surface flow numerical model is developed to calculate bed variations in alluvial channels. Vertically averaged free-surface flow equations in conjunction with sediment transport equation are numerically solved using an explicit finite-volume scheme using transformed grid in order to handle complex geometry fluvial problems. Convergence is accelerated with use of a multi-grid technique. Firstly the capabilities of the proposed method are demonstrated by analyzing subcritical and supercritical hydrodynamic flows. Thereafter, an analysis of one- and two-dimensional flows is performed referring to aggradation and scouring. For all reported test cases the computed results compare reasonably well with measurements as well as with other numerical solutions. The method is stable, reliable and accurate handling a variety of sediment transport equations with rapid changes of sediment transport at the boundaries. Copyright © 2002 John Wiley & Sons, Ltd.