| 摘要: |
| 建立了太湖三维风生流数值模型,并用差分法求解;垂直方向上采用了坐标变换技术,把任一节点的水深转换成无量纲水深,从而有效地消除了因风力作用造成的自由水面波动和湖底不规则的影响;水平面上采用锯齿网格处理,对于四周以闭边界为主的湖泊水域,显得比较合理。计算结果表明,湖泊风生流沿垂直、水平方向都有较大变化,流向上下、水平也并不一致,这是湖泊水流区别于其它水域水流之所在。计算模拟显示所建模型的有效性和可操作性。 |
| 关键词: 太湖 风生流 数值模拟 增减水 拟合变换 |
| DOI：10.18307/1994.0401 |
| 分类号: |
| 基金项目: |
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| A three-dimensional numerical simulation of wind-driven water current inTaihu Lake |
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Liang Ruiju1, Zhong Jinhua2
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1.Department of Water Resonrces and Hydrology, Hohai University, Nanjing 210098;2.Institute of Hydraulic Environment, Hohai University, Nanjing 210098
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| Abstract: |
| A three-dimensional numerical simulation on wind-driven current in Tauhu Lake is developed in this paper, in which the finite difference method is used.A dimensionless vertical coordinate is applied for the vertical grid regulation so as to eliminate the impacts of the wind-induced water level fluctuation and the irregular lake bottom forms, whereas grids with sawtoothed boundaries is applied along the horizontal dimensions when supposing the boundaries of the lake are closed.The wind data in July and August, 1988 are used in the numerical simulation of water level at Dapukou Station and Xukou Station.The comparison between the simulated and the observed results indicates certain cons is tan cy.Further studies reveal that, when a constant 14 m/s SE wind dominates for 20 hours on the water surface, the water level at Dapukou St.increases 45 cm while the level at Xikou St.decreases 40 cm.The four-layer (surface, upper-middle, lower-middle, near bed) velocity fields obtained respectively show that the absolute velocity of the surface flow is about 1.2 m/s, while the bed flow is between 0.3-0.6 m/s but in the opposite direction.The simulation also reveals that Che velocity field in the upper-middle layer change directions more frequently, which is in agreement with former researches done by foreigners.In conclusion, the wind-driven currents in lakes are very complicated, the representativeness of wind data is an important factor that affects the accuracy of numerical simulation.That the wind-induced current directions are vertically inconsistent and the velocity fields along the horizontal dimensions not evenly distributed is the characteristics of lake flow differed from that of other water bodies. |
| Key words: Taihu Lake wind-driven current numerical simulation increase and decrease of water level finite difference method simulation regulation |
