| 摘要: |
| 基于Blumberg等(1986)的河口、陆架和海洋模式,引入变边界处理技术,建立了胶州湾三维变动边界的潮流模型。模型以σ-正交曲线坐标下三维非线性潮波方程为基本方程,引入2.5阶湍封闭方程组。采用分裂算子法数值求解方程组。利用湍封闭方程求解垂直紊动粘滞系数,采用干湿网格方法模拟潮流漫滩过程。三维变动边界潮流模型计算结果与实测值吻合良好。 |
| 关键词: 胶州湾 数值模拟 变动边界 湍封闭 三维潮流 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，39790110-3号 |
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| A THREE-DIMENSIONAL VARIABLE BOUNDARY NUMERICAL TIDAL MODEL FOR JIAOZHOU BAY |
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SUN Ying-Lan, ZHANG Yue-Mei
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Institute of Environment Science and Engineering, Ocean University of Qingdao, Qingdao, 266003
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| Abstract: |
| A 3-D variable boundary numerical tidal model for Jiaozhou Bay is established in this paper. The model is based on a 3-D coastal ocean circulation model (Blumberg et al, 1986), and is modified by introducing dry-wet grid technology. A σ-coordinate transformation in vertical and a curvilinear coordinate in horizontal are used. The level 2.5 turbulence closure model is also used to give more reasonable vertical eddy viscosity coefficient. A split operator is used to calculate the finite difference scheme. A dry-wet grid technology is used to treat the tidal flood-ebb in tidal flat areas. An application of the model to the Jiaozhou Bay grasps the tidal characteristics well. The flooding tidal current mainly flows from the northeast to the southwest, with a part of it flowing into Jiaozhou Bay. The ebbing tidal current flow s from the southwest to the northeast with a part of it flowing out of Jiaozhou Bay. Maximum horizontal velocities of around 100cm/s occur at the bay mouth at the middle of the flooding and ebbing period. With water depth increasing, the value of horizontal velocity decreases. It decreases especially rapidly near the bottom. Its direction changes slightly in response to the changes in water depth. The average difference in flow direction between the bottom current and surface current is 3–5 degree. The occurring time of maximum current is earlier in bottom layer than in surface layer for about 10 minutes. The vertical velocity is of the order of 10-4m/s. It is significantly affected by the topography. The vertical velocity decreases when water depth increases, which a maximum of around 30×10-4m/s, occur ring near the bottom with a greater gradient of the topography at the bay mouth. The computed time of flood-ebb in the inner bay delays compared with the bay mouth for 16 min. The computed result in Jiaozhou Bay agrees with the observation well. It is significantly better than the result of the fixed boundary model. |
| Key words: Jiaozhou Bay, Numerical simulation, Variable boundary, Turbulence closure, Three-dimensional tidal current |
