In this paper a 2D model for the simulation of dam break events over a movable bed is presented. Based on a shallow water approach the model assumes the hypothesis of a watersediment mixture throughout (one-layer flow model) and takes into account non equilibrium transport of the sediments by means of an auxiliary relationship that introduces an erosion / deposition velocity. The governing equations are solved in coupled way by the implementation of an explicit first-order finite volume method. The application of the 1D version of the model to some experimental tests did not seem to differ significantly from other more complex models (Costabile & Macchione 2006). The main purpose of this work, therefore, is to analyze the performance of the 2D version of the model proposed by Costabile & Macchione (2006) in more complex geomorphic situations; in particular this study aims to find out whether the bed evolution law continues to work well when referred to a typical 2D behaviour of the dam break waves. Two applications are shown in the paper: the first one refers to a preliminary analysis of the performance of the 2D approach with reference to a dam break test case over erodible bed in a prismatic channel with rectangular cross section (Spinewine & Zech 2002); the second one refers to an experimental test carried out in a rectangular channel with an abrupt enlargement (Spinewine 2005). The numerical results shown in the paper provide encouraging results.
Numerical Simulation of 2D Dam Break Wave on Erodible Sediment Bed
COSTABILE, Pierfranco;COSTANZO, Carmelina;MACCHIONE, Francesco
2007-01-01
Abstract
In this paper a 2D model for the simulation of dam break events over a movable bed is presented. Based on a shallow water approach the model assumes the hypothesis of a watersediment mixture throughout (one-layer flow model) and takes into account non equilibrium transport of the sediments by means of an auxiliary relationship that introduces an erosion / deposition velocity. The governing equations are solved in coupled way by the implementation of an explicit first-order finite volume method. The application of the 1D version of the model to some experimental tests did not seem to differ significantly from other more complex models (Costabile & Macchione 2006). The main purpose of this work, therefore, is to analyze the performance of the 2D version of the model proposed by Costabile & Macchione (2006) in more complex geomorphic situations; in particular this study aims to find out whether the bed evolution law continues to work well when referred to a typical 2D behaviour of the dam break waves. Two applications are shown in the paper: the first one refers to a preliminary analysis of the performance of the 2D approach with reference to a dam break test case over erodible bed in a prismatic channel with rectangular cross section (Spinewine & Zech 2002); the second one refers to an experimental test carried out in a rectangular channel with an abrupt enlargement (Spinewine 2005). The numerical results shown in the paper provide encouraging results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.