长江上游航道三棱柱式人工鱼礁流场特性研究

Flow characteristics of triangular prism artificial fish reef in upper waterway of Yangtze River

一种新型的三棱柱式人工鱼礁在长江上游航道整治工程中已广泛应用,在改善水体流态和营造鱼类生境方面发挥着重要作用。通过数值模拟方法研究不同来流速度与布设间距下三棱柱式人工鱼礁上的流场特性,并提出人工鱼礁的最佳布置方式。研究结果显示,上升流最大速度与来流速度成正比,而上升流体积、上升流最大高度与礁高比值、背涡流体积和长度基本不受来流速度的影响。在同一流速下,上升流和背涡流体积均与人工鱼礁布置的横向间距成反比,与纵向间距呈先增大后减小的变化。横向及纵向间距分别为0.5倍和4倍礁长时为人工鱼礁的最佳布设方式。对比不同来流速度,上升流和背涡流区域特性参数受人工鱼礁布设间距的影响更明显。研究结论可为长江上游生态型人工鱼礁的建设提供理论依据。

A new type of triangular prism artificial fish reef has been widely used in the channel regulation project in the upper reaches of the Yangtze River,playing an important role in improving water flow dynamics and creating fish habitats.This study investigates the flow field characteristics on triangular prism artificial fish reefs under different inflow velocities and deployment spacings using numerical simulation methods,and proposes the optimal arrangement of artificial fish reefs.The research results show that the maximum velocity of upwelling is proportional to the inflow velocity,while the upwelling volume,the maximum height-to-reef height ratio of upwelling,the volume and length of back-eddy flows are not significantly affected by the inflow velocity.Under the same flow velocity,both the volume of upwelling and back-eddy flows are inversely proportional to the lateral spacing of artificial fish reef deployment,and they initially increase and then decrease with the longitudinal spacing.The optimal deployment configuration for artificial fish reefs occurs when the lateral and longitudinal spacings are 0.5 times and 4 times the reef length,respectively.Compared with different inflow velocities,the characteristics parameters of upwelling and back-eddy flow regions are more significantly influenced by the deployment spacing of artificial fish reefs.The research conclusions can provide theoretical basis for the construction of ecological artificial fish reefs in the upper reaches of the Yangtze River.