高盐度湖泊艾比湖风生流三维数值模拟
3D numerical modeling of wind-driven flow in the high salinity Aibi Lake
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摘要: 根据高盐度湖泊水动力特征,以西北咸水湖泊艾比湖为例,建立三维水动力数学模型。选取典型风场,分析风力作用下的高盐度湖泊风生流形成过程以及风生流水动力参数的三维空间分布特征。结果表明,艾比湖风生流形成在时间上可分为湖水流向和风向一致阶段、湖水运动方向逐渐偏离风向的过渡阶段及环流形成的稳定阶段等3个阶段。当流场达到稳定状态时,表层水体除中部存在若干小尺度环流外,大部分水域流向与风向基本一致;而湖泊中心区域底层水体流向与表层水体的流向大致相反,表现为很明显的补偿流。总体上,水平方向的流速自表层向下呈现递减的变化趋势,岸边流速大于中心流速,表现出与淡水湖泊基本相似的水动力空间分布特征。水体盐度增加对湖泊环流结构无影响。Abstract: According to the hydrodynamic characteristics of high salinity lake,a three-dimensional (3D)hydrodynamic numerical model is designed to simulate the dynamic in Aibi Lake which is a high salinity lake in northwest China.Selecting typical wind fields,we apply this model to simulate the formation process of wind driven flow and 3D spatial distribution characteristics of hydrodynamic parameters.The study result shows that the formation process of wind driven flow can be divided into three stages:The flow direction is consistent with wind direction,the flow direction deviates from the wind direction in the transitional stage and the current ultimately forms a circulation stable stage.When the flow field is on steady state,the flow direction in most of the waters are in consistent with the wind direction while there are several small scale circulations in central.The bottom current in central is opposite to the surface one with a compensation current character.Overall,the horizontal velocity from the surface to the bottom is decreasing.The inshore velocity is greater than the central one.It shows that the distribution characteristics of hydro-dynamic parameters in high salinity lake are similar to that of fresh water.Increased water salinity has no effect on the structure of lake circulation.