摘要
为了既能精确地拟合不规则区域边界,又使有限差分的计算能在规则的网格上进行,在长江口南支河段非恒定流的平面二维数值模拟中,采用了近年来得到广泛注意的边界拟合坐标法,为了提高计算的稳定性,本文引用了二维人工粘性项和人工光滑的方法。计算结果与实测资料相当吻合。计算结果还表明,在同样的网格密度下,使用边界拟合坐标的差分计算的CPU仅比使用昔通网格的差分计算略有增加。所以,在二维水流计算中,这是一种值得推荐的方法。
In order to follow correctly the complex geometry of the boundary of the flow field,a body-fitted coordinate system was employed in simulating horizontally 2-D flow field of the Yangtze estuary.The body-fitted coordinates are generated with the solution of a couple of elliptic equation. To perform the finite difference computation in a regular mesh,the inverse mapping equations are used in real computation.The system of equations was solved by operator-splitting method.The implicit finite difference scheme and staggered grid mesh were applied in obtaining the numerical solution.In order to improve the stability of the scheme,2-D artificial viscosity and 2-D smoothing procedure were introduced.The boundary conditions for computation are as follows:discharge hydrograph at upstream cross-section;tide elevation at downstream cross-section;normal component of velocity V_n=0 at land boundary.The results obtained from the computation are in satisfactory agreement with field measurements.
出处
《河海大学学报（自然科学版）》
CAS
CSCD
1989年第1期50-57,共8页
Journal of Hohai University(Natural Sciences)
关键词
非恒定流
边界拟合坐标
数值模拟
body-fitted coordinates
operator-splitting
2-D artificial viscosity
