太湖梅梁湾、贡湖套网格风生流数值模拟

Nested grid-based numerical simulation of wind-induced current of Meiliang Lake and Gonghu Lake in the Taihu Lake

对太湖梅梁湖、贡湖湖流进行套网格数值模拟。根据1998年8月太湖富营养化水质监测水文物理资料,绘制出梅梁湖、贡湖各站点位置分布图和其流速大小和方向。模拟计算与实测结果吻合较好,证明其套网格数值模型的建立是合理和有效的。分析结果表明,太湖各水域流速相差很大,近岸区域流速高于远岸区域,存在明显的近岸流。但流速值不大,即梅梁湖、贡湖和大太湖的水体交换量不大,通过流场分布可初步判断污染物质在水体中的扩散与迁移情况。

According to the hydrological data obtained from the water quality eutrophication monitoring performed for the Taihu Lake in Aug. 1998, the distribution of various observation stations for the Meiliang Lake and Gonghu Lake are drawn, and the value and direction of the flow velocity are also derived. The good agreement of the calculated results with the measured data demonstrates the rationality and effectiveness of the nested grid numerical model. Analysis shows that great differences exist between the flow velocities of different areas of the Taihu Lake, the flow velocity of near-shore areas being higher than that of off-shore areas, so there exist obvious near-shore currents, and that there′s little exchange between water bodies of the Meiliang Lake, Gonghu Lake, and the whole Taihu Lake due to the small velocity in these areas. By analysis of the flow field, the diffusion and transport of pollutants in water bodies can be estimated primarily.