Analysis Analysis Of Unsteady Flow And Vibration Vibration Characteristics Of Low Specific Based On Two-way Fluid Characteristics Of Low Specific Speed Centrifugal Pump Way Fluid-structure Interaction Pump

Low-specific-speed centrifugal pump with small flow and high head characteristic is widely used in petrochemical,pharmaceutical and power industries.Centrifugal pump operation will appear vibration phenomenon.Vibration may cause damage to the centrifugal pump,reduce performance and reduce service life,but also lead to noise.It is essential to improve the smooth operation of centrifugal pumps.The hydraulic excitation force generated by unsteady flow in the pump is one of the main reasons leading to the unstable operation of the centrifugal pump.The vibration caused by the unsteady flow of the pump inside the pump will seriously affect the safe and stable operation of the centrifugal pump.In this paper,CFD software and FEM software are used to calculate the relationship between unsteady flow and impeller vibration:(1)Pro/E software is used to establish the three-dimensional model of the whole flow field of the low-specific-speed centrifugal pump,including shroud side chamber,hub side chamber and wearing clearance.The software ANSYS ICEM is used to generate grid.Based on the SST(Shear Stress Transport)k-? turbulence model,the flow field in the pump is calculated statistically,and the distribution of pressure,velocity and axial vortex in the centrifugal pump is analyzed.(2)The pressure pulsation on the volute is obtained by two way coupling and non-coupling.The simulation results are compared with the experimental results,found that two kinds of simulation results are in good agreement with the experimental results,and variation is consistent.There are eight peaks in one circle,and the number of the peaks is the same as the number of impeller blades.(3)In order to understand the variation of radial force under unsteady flow,the radial force on the impeller and the radial force on the blade are analyzed.The results showed that the radial force on the impeller is periodic,as the flow rate increases the radial force on the impeller increases;radial forces on the leaf blade have abrupt changes when the blade sweep the tongue,the smaller the flow rate is,the more obvious the change is.(4)The natural frequency and mode modes of the first ten order modes are obtained by modal analysis of the rotor system.The impeller displacement of the impeller at different flow rates is analyzed.With the increase of the flow rate,the vibration displacement of the impeller increases,and the vibration displacement is irregular at small flow rate.