厦门海域二维潮流数值计算

Numerical simulation of two-dimensional tidal current filed in Xiamen Waters

厦门附近海域面积辽阔且水深较浅,潮差较大,潮流流速u、v水平变化远大于垂向变化,可用二维浅水波方程组描述其潮波运动.利用欧拉-拉格朗日差分方法得到数值解,模拟了厦门附近海域潮流场,并采用随时间变化的动边界技术,模拟了大面积浅滩淹没和干出的情况,还对同安湾、西海域及九龙江使用嵌套网格模拟以提高精度.计算结果显示N1站涨潮流向约为330,°落潮流向约为150,°N3站最大流速达0.77m/s.与实测结果对比验证表明计算结果是可信的.

The waters near Xiamen are open and shallow. With high tidal head, the variation of current velocity in horizontal direction is much greater than vertical direction. A two-dimensional shallow flow equation is used to describe the tidal currents, and an Eulerian-Lagrangian semi-implicit finite difference method is applied to simulate the current field in this area. To improve the precision in simulation, a nested grid is used in Tongan water area and Xiamen western waters. Due to the wide area of flood and desiccation, a variable boundary technology is used. The result shows that the flow direction of rising tide at N1 station is approximately 330° ,the flow direction of ebb tide is about 150°. The maximum velocity of N3 station is 0.77m/s. The computed results match well with the observations.