Experimental Study And Numerical Simulation Of Hydraulic Characteristics Of Conical Fishway

Fish way as a kind of fish conservation water conservancy project plays an important role in maintaining river connectivity and protecting fish species diversity.As a new type of pond weir fishway,the conical overflow weir fishway is widely used because it is suitable for low head engineering,simple structure,good effect of fish crossing and low economic cost.Based on the cone overflow weir fishway as the research object,USES the Acoustic Doppler velocity(&Doppler Velocimeter,ADV)technology and Computational Fluid Dynamics,Computational Fluid Dynamics,CFD)numerical calculation method,through physical model test and numerical simulation research,systematically studied the different hydraulics parameters influence on the flow regime in the fishway,analyzed the flow pattern of fishway pool room,velocity distribution and turbulent kinetic energy distribution,The design and operation parameters of the conical overflow weir fishway are optimized by means of the experimental study of fish's retrograde ability and the forms of different fishway.The main conclusions are as follows:1%The ADV technique is used to test the flow field of a conical weir type fish path.It is found that the flow velocity in the conical overflow weir is satisfied with the requirements of the fish path,the proportion of the area in the rest area is more suitable and the flow characteristics of the "S" type can be produced.The study of the plane flow field and the vertical flow field of the pool shows the internal water.The flow is mainly flat 2-D flow,and the distribution of flow field is suitable for the upward migration of fish.2?Using the computational fluid dynamics(CFD)numerical method the fishway building numerical calculation model,and for solving the flow characteristics of fishway,based on the flow field distribution in different fishway structure optimization of fishway design.The model can simulate the measured results well,and the basic error of the velocity is less than 5%,which indicates that the model can be applied to the simulation study of the hydraulic characteristics of the fishway.3.the structure of fishway for greater influence on the distribution of flow field in the fishway,weir on both ends of the radius mainly affect the structure and flow within the fishway,major effect in the fishway velocity gradient,length-width ratio on velocity and flow structure,the numerical simulation results show that when the radius of 40 cm and 20 cm on both ends of the weir,slope was 1%,the aspect ratio of 1.5:1 for the optimal form.4.The conical weir type fish passage has a large recirculation zone at the bottom,and the turbulent energy in the fish path is small.The same is the calculation of the energy consumption of the traced path of the fish way fish.It is found that the weir type fish path is suitable for the backtracking of the Qinghai Lake huangfish.The reversible mainstream of the fish with strong swimming ability can be traced back quickly,and the fishes with weak swimming ability can use the reflux area after the weir to take a short rest.