结构变化对鱼道水力学特性的影响

除了鱼池长宽比、隔板墩头和隔板结构的改变会对鱼道的流速、流态等水力学特性指标产生影响之外,底孔和坡度等对流速和流态的影响也不能忽视。为了研究底孔和坡度对鱼道的流速、流态等水力学特性指标产生的影响,采用标准k-ε湍流模型对不同工况的鱼道进行了数值模拟计算。研究表明:竖缝式鱼道的最大流速一般出现在竖缝附近,并且对于竖缝处的测点,一般是底层流速更大;增加底孔会降低竖缝处的流速,但底孔处流速偏大;放缓坡度一半时,竖缝处平均流速会降低约20%以上,因此就流速而言,放缓坡度会降低鱼道中的流速,从而对鱼类洄游有利。本实验不仅验证了此次数值模拟计算结果的可靠性,也直观地将鱼道流态清晰展示出来。

Influence of Structure on Hydraulic Characteristics of Fishway

In order to research the impact of bottom hole and slope on the hydraulic characteristics of velocity and flow pattern in fishway,a series of numerical simulation on three different working conditions were done by the k-ε turbulence model.The results showed that in vertical slot fishway,the maximum velocity usually appears near the vertical slot,and the velocity at the bottom layer is higher than other layers.The bottom hole at the central baffle would slow down the velocity at the vertical slot,but the velocity would be very high at the bottom hole.When the slope of the fishway changes from 5.2% to 2.6%,the average velocity at the vertical slot decreases more than 20%.It was concluded that the gentle slope is beneficial to the migration of the fish in terms of velocity.