基于Mike21模型的湖泊推流设计

Design of lake pushflow based on Model Mike21

构建了基于Mike21的推流器水动力模型,以西湖沉淀区为研究对象,对不同工况的推流效果进行模拟。基于推荐工况,沉淀区西侧的平均换水率在7 h内基本趋于稳定;但沉淀区东侧换水率需16 h才达到基本稳定,较西侧有所降低。结果表明,在工程中采用7.5 kW推流器(1用1备),沉淀区西侧实测平均流速0.213 m/s,与模拟值仅偏差7.9%,工程达到了预期的效果。基于Mike21的推流器水动力模型在西湖沉淀区项目的成功应用,不仅解决了推流方案的比选优化问题,还可为其他城市内湖的水动力改善提供理论基础和技术支持。

A hydrodynamic model of the water impeller based on Mike21 was constructed,and the impelling effects of different working conditions were simulated with the sedimentation zone of the West Lake as the research object.Based on the recommended working conditions,the average water changing rate on the west side of the sedimentation zone tends to be stabilized within 7 h.However,the water changing rate on the east side can only achieve stabilization in 16 h,whose efficiency was lower than that of the west side.Results show that when the 7.5 kW impeller(one for use and one for stand-by)is used in the project,the measured average velocity on the west side of the settling zone is 0.213 m/s,with only a difference of 7.9%when compared with the simulation value,achieving the expected effect.The successful application of the impeller's hydrodynamic model based on Mike21 in the settling zone of the West Lake not only solves the problems about the comparison,selection and optimization of the impelling scheme,but also provides a theoretical basis and technical support for hydrodynamic improvement in lakes of other cities.