High Water Head And Long Distance Inverted Siphon Hydraulic Characteristics And Structure Stability Study

In this paper,based on the background of the inverted siphon project in the middle of Qinghai Province,this paper analyzes the hydraulic characteristics of the inverted siphon model by using the professional fluid calculation software FLUENT,and then analyzes the hydraulic characteristics under the condition of the design condition.MPCCI platform is used to establish FLUENT and ABAQUS coupling interface.The three-dimensional model of the bottom of the inverted siphon is designed by using the finite element software.The stress and strain characteristics of the bottom pipe section of the inverted siphon are analyzed by the two-way fluid-solid coupling calculation.The results of the calculation show that:(1)The maximum water level of the inlet and outlet sections is 2712.8m and2705.8m,respectively.The calculated head loss is close to the theoretical calculation and the relative error is 4.1%.(2)The maximum flow rate of the inlet section is 9.6m/s,and the flow velocity of the pipe shaft is 1.9m/s,which is reduced to 1.3m/s,inverted siphon tube or bend the maximum flow rate deviation from the tube axis position down,the maximum pressure2.72 MPa is located in the bottom of the inverted siphon.(3)The water level during the process of inverted siphon 2 # pipe section at the top of the existence of airbags,can not be self-discharge,need to be in the 2 # and 3 #pipe joints at the integrated exhaust valve set to reduce the pipeline vibration.(4)The static calculation results of the bottom pipe structure of the inverted siphon show that the maximum stress appe-ars at the top and bottom of the edge of the joint between the pier and the pipe,the va-lue is 13.2MPa;the maximum displacement appears in the pipe and branch The middle position of the pier is vertically downward and has a value of 0.0027 m.(5)The two-way fluid-solid co-upling calculation of the bottom pipe structure of the inverted siphon shows that there is strong vibration in the initial stage,the maximum stress is 95.3MPa,the maximum displacement is 0.084 m,the maximum stress after stabilization is 76.4MPa,the max-imum displacement of 0.004 m.The modal analysis results show that the minimum res-onant frequency of the pipeline is1.6071 Hz.