Study On Hydraulic Characteristics Of The Fishway Based On Combination Of Vertical Slot And Imitation Ecological

With the growing awareness of environmental protection,the research and construction of the fish pass is imperative in order to coordinate the relationship between dam construction and ecological environment,maintain the original ecological connectivity of the river,and reduce the impact of the hydraulic engineering on migratory fish species.In the actual engineering,the layout of the fishway is affected by the terrain,landform,water level,and environment,and the arrangement type combined by vertical slot and imitation ecological has better adaptability,so it is necessary to study the fishway of this arrangement type.This paper takes the fishway of the Jinggangshan Hydropower Engineering as the research background.By establishing a normal whole model with a geometric scale of 1:10 for the physical model test and using a RNG k-? model for establishing a three-dimensional mathematical model for numerical simulation,the hydraulics characteristics of the fishway combined by vertical slot and imitation ecological were studied.Research content and results are as follows:(1)summarizes the development history and research progress of fishway at home and abroad,and summarizes the characteristics of fish migration and swimming,the layout of fishway,and the classification and characteristics of fishway.(2)Through the physical model tests,the variation of water depth in each chamber,the maximum flow velocity in each chamber,the flow pattern in the chamber and the cohesion of vertical slot and imitation ecological,and the velocity distribution in the chamber were studied under three conditions.The results show are as follows: the flow pattern at the cohesion of vertical slot and imitation ecological is good,and the flow pattern of each chamber is stable,which proves that the combination is feasible.The change of water depth in the chamber mainly affects the mainstream flow velocity,and the greater the water depth in the chamber,the smaller the maximum flow velocity in the chamber and the mainstream flow velocity,and less impact on flow rate in recirculation zone.(3)The three-dimensional mathematic model of the fishway combined with the same vertical slot and imitation ecological as the physical model test was established,and the established three-dimensional mathematical model was verified and verified using the measured data of the physical model test.The results show that the measured data of the physical model test are very close to the results of the numerical simulation,indicating that the mathematical model can be used for the numerical simulation of fishway,and the calculation results have high credibility.(4)Using a validated three-dimensional mathematical model for numerical simulation to research on four different shapes of imitation ecological fishway,analysis of the passed flow,chamber flow patterns,flow velocity distributions,and turbulent kinetic energy,the results are as follows: four different types of imitating ecological fishway can meet the flow matching requirements combined with the vertical slot fishway.The main stream of the type 2 is similar to that of the type 1,but the installed submerged hole communicates the recirculation area of the front and rear chambers,which improves the water depth distribution in the chamber.The main stream of the type 4 is similar to that of the type 3.However,the mainstream range of type 4 is more concentrated,and the range of the recirculation area behind the middle pier is smaller,and the recirculation area on the main stream is more symmetrical.The change of turbulent kinetic energy in the chamber is similar to that of the flow velocity.