| 引用本文: | 胡维平,濮培民,秦伯强.太湖水动力学三维数值试验研究─2.典型风场风生流的数值计算.湖泊科学,1998,10(4):26-34. DOI:10.18307/1998.0404 |
| Hu Wei-ping,Pu Pei-min,Qin Bo-qiang.A Three-Dimensional Numerical Simulation on the Dynamics in Taihu Lake，China(H)： the Typical Wind-driven Current and Its Divergence. J. Lake Sci.1998,10(4):26-34. DOI:10.18307/1998.0404 |
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| 摘要: |
| 本文用垂直方向均分五层,水平网格距离为1km的压缩σ坐标系下的三维数值模型,计算了太湖典型风场SE,NW,SW风生流.分析了太湖湖流及由各层流场平均得到的整层平均流态在这三种典型风场作用下随时间的演变特征；探讨了风应力、水面倾斜压强梯度力、湖底摩擦力三者对湖流垂直结构的影响,初步揭示了太湖湖流垂直结构形成的机理. |
| 关键词: 三维数值模拟 风生流 散度 太湖 |
| DOI：10.18307/1998.0404 |
| 分类号: |
| 基金项目:欧盟项目,CI1*-CT93-0004（DG12-HSMU）;中国科学院“九五”重点项目,KZ952-S1-220 |
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| A Three-Dimensional Numerical Simulation on the Dynamics in Taihu Lake，China(H)： the Typical Wind-driven Current and Its Divergence |
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Hu Wei-ping, Pu Pei-min, Qin Bo-qiang
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Nanjing Institute of Geography Limnology, CAS, Nanjing 210008
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| Abstract: |
| The water currents in Taihu Lake driven by 8. 0 m/s SE, SW and NW wind were calculated by using the three-dimensional model，in which the water depth was normalized to 1, the water column equally divided into five layers and the time step and x，direction step were 120s and lkm respectively. Hencc, the lake currents developments and the average currents along the vertical direction were analyzed. The influences of wind stress, water pressure gradient force, frictional stress of Taihu Lake bottom on the vertical structure of water current were considered as well.The forming mechanism of vertical current structure was revealed initially. At the beginning of the wind, such as after.lh, the flow decreased gradually from surface to middle layer, but the deviation from the wind direction was small, no more than 20。，while in the middle to bottom layer, there was a small flow with a direction typically different from the wind direction. As time went by, with the water accumulated in the windward area，the water pressure gradient force became big, so the flow decreased at the surface layer and increased at the bottom layer. After a typical wind has dominated for 12h, a stable flow field was formed in the open Taihu Lake. At the surface layer the deviation angle of the flow in center Taihu Lake was about 20°, the current was evenly distributed and the flow was smaller than that after lh. At the layer under the surface layer the flow field distributed irregularly, with smaller flow when comparing with those on the surface and middle layer, and directions changed dramatically at different network points. At the middle layer, the flow field were evenly distributed, with an angle of more than 90° deviated from the wind direction. At the bottom layer and its upper layer, the flow field were also distributed evenly, with an direction adverse of the bottom flow, which were due to the compensation flow of the surface water flow. At the upper part of the bottom layer the flow was bigger than those on the bottom and middle layer.It was also shown that in the bay and semi-closed area flows were stable, even after the wind has blewn for 48 h. There were divergence and convergence on each layer. At the beginning,the divergence and convergence were strong. There was sinking area in the Ice side and upwelling area in the windward side. As time went by, the divergence became weak and the upwelling area became large,The model revealed that there existed wind-stress-dominated area, water-prcssure-force-dominated area and bottom-frietion-foree-dominated area vertically. |
| Key words: Three-dimensional numerical simulation wind-driven current divergence Taihu Lake |
