Experimental And Numerical Simulation Of Fluid-structure Interaction Pipeline Vibration

In the pipeline, there is fluid-structure coupling which is due to the interaction between the fluid and the pipe, due to the unstable state of fluid flow, lead to internal fluid pressure imbalance to generate pressure fluctuation causing the pipeline vibration, the vibration effects on elbow, valve and pipeline connection parts, will lead to pipeline leakage phenomenon, and in extreme cases tube-burst accident may occur. From the Angle of guarantee the safety of water conveyance pipeline, based on the theory of fluidstructure interaction, the gravity flow and pressure flow study two different water supply mode, through to the steady state vibration data, close the valve, the pressure data collection, as well as the application of numerical simulation technology to monitor the pipeline characteristics of the fluid-structure coupling vibration.First of all, the construction of the experimental pipeline system, organic glass tube as pipe material, by high and low water tank and gravity flow pressure flow of pipeline, pipeline total length of 75 m, the pipe through the pump and valve adjusting velocity between 0-2.3 m/s, simulated in gas-liquid two phase flow fluid, gas with air pump, add volume between 0 and 1.5 m3/h. In two pipelines, contain rising section, decreased section and horizontal section to simulate the water pipe because of the terrain ups and downs and there are many slope section. Set electric butterfly valve control flow for steady-state vibration test and analysis, the vibration data with acceleration sensor; Through pneumatic butterfly valve quickly closed valves closed to simulate water hammer experiment, collecting water hammer pressure changes with pressure sensor data.Data analysis and test results show that the steady state vibration test, in the singlephase flow, pipe radial vibration intensity is small, and the intensity of axial vibration increases with the flow, in the gas-liquid two phase flow, due to the existence of the gas pipeline vibration condition is complicated, down pipe in pipe vibration under the influence of gas rate is large, compared to single phase flow under the same velocity, the axial and radial vibration intensity are larger that the existence of the water gas can make the pipe under the condition of steady-state vibration more intense, is not conducive to stable operation. To close the valve water hammer pressure test, close the valve of water hammer with velocity increases, the water hammer pressure value and under the same flow rate, as, with the increase of gas valve water hammer pressure value decreases, and this is due to the compressibility of the gas in gas liquid two phase flow, effectively reduces the strength of the valve water hammer. In extreme flow change, the existence of the gas in the fluid will have certain protective effect on the pipe.In the numerical model analysis, through the ANSYS Workbench valve experiment was carried out numerical simulation research. By establishing a consistent with the experimental pipeline uniflow solid coupling numerical analysis, physical model of the fluid pressure change nephogram and wall deformation nephogram change, on the analysis of the water hammer have more intuitive.Solid coupling phenomenon of multiple perspectives through the water pipe, working condition of more comprehensive analysis, summarized the water pipe of fluid-solid coupling vibration characteristics of the test data and conclusion of the water pipe design, management, provides a theoretical basis has a certain reference value.