Study On Fluid-induced Vibration And Noise Characteristics Of Water Pipe Valve

Valve vibration noise is one of the main sources of vibration noise in pipeline system.It is very important to study the characteristics of valve vibration noise for vibration and noise reduction in pipeline system.In the past,the research on valve vibration and noise is mostly confined to the characteristic analysis under steady state or constant opening,but rarely to the variable condition characteristic of the transient valve opening and closing process.Therefore,this paper takes the ball valve as the research object,on the basis of analyzing the steady state characteristics of the ball valve under the constant opening,studies the dynamic characteristics of the ball valve in the transient opening and closing process.The specific research contents are as follows:The finite element model and flow field model of the ball valve structure were established.By comparing the dry-wet modal test and simulation results,the boundary parameter modification method was adopted to modify the stiffness of the three-way spring,and the actual installation boundary conditions of the ball valve were obtained.By using the modified boundary conditions,the flow induced vibration test of constant opening ball valve is compared with the simulation data,and the results are in good agreement,which verifies the accuracy of the numerical calculation method of flow induced vibration in this paper.On this basis,the flow field characteristics of ball valve with constant opening were analyzed to explore the flow-induced vibration mechanism of ball valve,and the influence law of different mass flow rate and opening on the flow-induced vibration characteristics of ball valve with constant opening was studied.The ball valve sound field model was established,and the empirical formula and Lighthill sound analogy method were used to calculate the ball valve flow noise under constant opening respectively,which verified the effectiveness of the calculation of ball valve flow noise under constant opening in this paper.On this basis,the opening under different mass flow rate is studied and the effects of opening on the ball valve flow noise,and analyzed on the basis of the principle of sound and solid coupling under fixed opening ball valve structure acoustic radiation characteristics,the results show that the opening,the greater the overall flow noise amplitude,the greater the peak sound pressure level of the frequency value is smaller,but the loudest under different opening level always appear in the center of the valve core.Based on dynamic grid and the ball valve of UDF technology to achieve the dynamic simulation of the transient process of opening and closing,studied and analyzed the different inlet mass flow rate,opening and closing valves open and close valve speed curve length and the dynamic characteristics of a ball valve transient opening and closing process flow field,the influence of transient found in ball valve opening and closing process,the inlet mass flow rate,the greater the center position of the velocity and pressure in the valve range is larger;The longer the opening and closing valve is,the lower the disordered degree of flow field and the maximum flow velocity are under the same opening degree.The smaller the slope of valve opening velocity curve is,the velocity gradient of fluid in the valve and the degree of flow field disorder decrease.At the initial moment of valve opening,the jet velocity at the inlet side and outlet side of the valve core also decreases.Based on the two-way coupling method and dynamic grid technique under different working conditions,to study the fluid pressure acting on the valve core features,analysis of the transient opening and closing valve core in the process of changing trends in the viscous force and total force,and the transient flow induced vibration characteristics of the ball valve opening and closing process was studied,and the safe operation of the valve is in the transient conditions to provide the reference.