2D numerical modelling of dam break- applying for Namchien dam in Vietnam

Abstract

The paper is dedicated to study a numerical model simulating dam-break based on two dimensional nonlinear shallow water equations (2D-NSWE). Finite Volume Method-Godunov type is applied to discretize this equation. Roe scheme is utilized to approximate Riemann problem, meanwhile method of flux difference splitting is implemented to construct numerical solvers of SWE. Besides, the semi implicit scheme is also invoked to solve friction term in case of high roughness coefficient. The proposed model is verified through a comparison between computed results and empirical data of two reference tests. A dam break flow over floodable area with different roughness coefficients is also researched. A total collapsed dam scenario of an arch dam-Nam Chien in Vietnam is simulated by the proposed model. Several hydraulic characteristics such as flood extent, arrival time and time histories of water depth at different gauges are estimated with different grid sizes.

A Comparison of Numerical Schemes for Simulating Reflected Wave on Dry and Enclosed Domains

“…A numerical code, namely 2D-FVM, based on both HLLC and ROE schemes, was written in the Fortran language by the first author. This program has been successfully applied for dam-break wave simulation in previous research [25,26]. However, the 2D-FVM model still has some limitations, such as: (i) the numerical scheme is explicit, so time-consuming, and expensive; (ii) using structure mesh in all computational domains cannot capture well hydraulic characteristics at the complex domain or abrupt topography.…”