水利学报Issue(z2)：41-47,7.
一维浅水流动的一种大时间步长数值格式
A large time step scheme for free surface shallow water equations
摘要
Abstract
The LTS (large time step) scheme is firstly applied to numerical simulation of 1-D free surface shallow flows to obtain high resolution and efficiency. This scheme is firstly proposed by LeVeque based on Godunov method. It is developed and applied to Euler equations in aerodynamics by Qian. Traditional Roe scheme is replaced by exact Riemann solver with wave propagation method and single-wave approximation shows that the resolution is improved when CFL number is smaller than 1. When CFL number is larger than 1,two instead one-wave approximation must be applied to maintain the result acceptable. Some simpli⁃fication is applied to the two-wave approximation in this paper compared to the method used by Qian in aerodynamics. When CFL number is larger than 10,wave interaction method is imposed to the scheme to maintain the results stable. Although slightly spurious oscillations might also appear for when CFL number is larger than 5, the numerical stability does sustain up to CFL=15 in the present study and the oscilla⁃tion can be controlled in a little scope. Computational time comparisons show that the scheme improves the efficiency greatly when the large CFL numbers are imposed.关键词
大时间步长/浅水流/黎曼求解器/行波法/CFL数Key words
large time step/shallow flows/Riemann Solver/wave propagation method/CFL number分类
建筑与水利引用本文复制引用
许仁义,钟德钰,吴保生..一维浅水流动的一种大时间步长数值格式[J].水利学报,2012,(z2):41-47,7.基金项目
国家973项目（2011CB403304）；国家自然科学基金项目 （）
