The Fluid-solid Coupling Structure And Dynamics Analysis Of The Welted Bifurcated Pipe In The Hydropower Station

The pressure pipeline is an important structure for water supply from the reservoir,the front pool or the surge tank to the turbine in the hydropower station.The welt pipe is widely used in the pipeline system of the medium and low head power stations.In this paper,according to the structural mechanics algorithm,fluid-solid coupling and structural dynamics theory,the Ansys finite element method is used to analyze the structural stress and natural vibration characteristics of the welt pipe and simulate the continuous harmonic external excitation.Dynamic response.The research on the harmonic response of the dam can accurately simulate the vibration effects under the actual working conditions of the hydropower station,and has certain reference value for the deformation,fatigue and damage of the pipeline system.The main work of this paper is as follows:1.Use the finite element software ANSYS Workbench to establish a fluid-solid coupling analysis that conforms to the welt tube by selecting and contacting each module in the Toolbox.Taking the welt pipe as the research object,the influence of bidirectional and single fluid-solid coupling on the stress and displacement of the water conveyance manifold at different angles was considered and compared.The different mesh density,the width of the reinforcing plate and the thickness of the reinforcing plate were also studied.The effect on structural stress and displacement.Through the comparative study of the results,it has certain reference value for the actual project.2.Using the finite element software ANSYS Workbench to establish a fluid-solid coupling modal analysis that conforms to the welt tube by selecting and contacting each module in the Toolbox.The modal analysis is used to simulate the design of the pipe and the vibration characteristics of its components,namely the natural frequency and mode shape of the structure.The obtained modal and vibration modes are important parameters in the design of dynamic load structures,and can also be the starting point for other dynamic analysis problems such as harmonic response analysis,transient dynamic analysis and spectral analysis.3.Use the finite element software ANSYS Workbench to establish a fluid-solid coupling analysis that conforms to the welt tube by selecting and contacting each module in the Toolbox.The three-dimensional water conveyance pipeline model is built by simulating the common welt pipe.The dynamic characteristics of the welt pipe under the fluid-solid coupling are considered by considering different factors.On the basis of the modal analysis,the sound is simulated to simulate the mechanical generation of the pump.The periodic continuous external excitation focuses on the dynamic characteristics of the harmonic external excitation and the resonance of the pipeline structure.The results show that in the actual engineering design,the welts of the various forms and boundary conditions need to avoid the first-order natural vibration frequency.Through the numerical simulation results of this paper,it has certain reference to the design,safety and reliability of the welt piping system.