洋沙泡风生流强度数值模拟分析

Numerical simulation of wind-driven current intensity in Yangsha Pao

洋沙泡作为浅水湖泊是白城市主要灌溉及饮用水水源,内源污染是影响其水质的主要原因。为查明风生流对其水环境的主要影响,利用MIKE21建立洋沙泡二维水动力模型,采用单一控制变量法,模拟了风速、风向和引水流量对洋沙泡风生流强度的影响进行分析。结果显示,风速是影响风生流强度的最主要因素,这与其较浅的水深有关,与4m/s风速相比, 7m/s风速作用时整个湖泊流速平均增长63.6%,盛行风向作用下风速越大湖流流速越快;引水流量对湖流流速的影响范围有限,仅会影响引水口周边水域的水流流速,但湖泊整体流速减慢了4.9%;风向的改变会直接导致环流流向的变化,西南风和东北风分别作用时,洋沙泡湖流流速并没有明显的差别。研究结果可为洋沙泡日后的水环境治理提供流场分布数据。

Yangshapao,as a shallow lake,is the main source of irrigation and drinking water in Baicheng City.Endogenous pollution is the main reason that affects its water quality.In order to find out the main influence of wind-driven flow on its water environment,a two-dimensional hydrodynamic model of Yangshapao was established by using MIKE21,and the effects of wind speed,wind direction and diversion flow on the intensity of wind-generated flow were simulated and analyzed by using single control variable method.The results show that wind speed is the most important factor affecting the intensity of wind-generated flow,which is related to its shallow water depth.compared with 4 m/s wind speed,the average flow velocity of the whole lake increases by 63.6% under the action of 7 m/s wind speed,and the higher the wind speed under the prevailing wind direction,the faster the lake flow velocity;the influence of diversion flow on lake flow velocity is limited,which only affects the flow velocity of the waters around the diversion mouth,but the overall flow velocity of the lake slows down by 4.9%.The change of the wind direction will directly lead to the change of the circulation direction,and there is no obvious difference in the flow velocity of the Yangshapao lake when the southwest wind and the northeast wind act respectively.The research results can provide flow field distribution data for the treatment of water environment in the future.