北方浅水湖泊冬季结冰对风生流的影响  

Study on wind-driven flow under the influence of water freezing in winter in a northern shallow lake

作　　者：陈友媛[1,2] 胡广鑫[2] 杨世迎[1,2] 李亚平[2] 

机构地区：[1]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100 [2]中国海洋大学环境科学与工程学院,山东青岛266100

出　　处：《水科学进展》2012年第6期837-843,共7页Advances in Water Science

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07106-003)~~

摘　　要：为了研究北方浅水湖泊冬季结冰对风生流的影响,采用MIKE21构建山东省聊城市东昌湖水动力学模型,分析真实风场作用下6种风应力拖曳系数对应的模拟流速与实测数据的差异,进一步讨论了冰盖面积对模拟结果产生的影响。结果表明,风应力拖曳系数为随风速连续变化比设置为常数模拟精度提高20%左右,其中采用微风条件下的风应力拖曳系数表达式模拟效果最好。此外,冬季水体结冰对风生流数值模拟影响较大,尤其是在被冰盖所覆盖的水域,风应力对水体流动的作用减弱甚至被抵消。与传统的风生流模拟相比,在北方浅水湖泊冬季风生流模拟中,引入冰场或是对风应力拖曳系数进行相应调整是有必要的。Six empirical formulae of the wind drag coefficient were considered in a MIKE21 hydrodynamic model to study properties of wind-driven flow in a shallow lake in the northern city （Dongchang Lake in Liaocheng, Shang- dong, China） under a real wind condition. Moreover, the influence of ice cover area on simulated result was also ana- lysed. The results showed that the accuracy was improved about 20% when the wind drag coefficient was varied with real wind field than when it was constant. That is, the model with real wind could accurately describe the wind-driven flow process of the Dongchang Lake. Among the six formulae of the wind drag coefficient, the one proposed under breeze condition was best. Freezing water has significant effected on numerical simulation of wind-driven flow, espe- cially in the zone of ice cover. The influence of wind stress on water flow has been weakened or counteracted under water freezing. Compared with the traditional w{nd-driven flow simulation, it was necessary to consider ice condition or to adjust the wind drag coefficient in MIKE21 in a northern shallow lake. The results might give a reference for the water resources management in a northern shallow lake.

关 键 词：风生流 真实风场 风应力拖曳系数 MIKE21 冰盖 东昌湖 

分 类 号：TV131.4[水利工程—水力学及河流动力学]