Vibration Analysis And Optimization Of The Mixed Flow Pump Characteristics

As a kind of widely used machine,pump is applied in various areas such as petrochemical industry,steel and mining,spaceflight and navigation,urban water supply and drainage system,etc.In recent years,the requirements of industrial improved continuously.Water pumps not only needs to meet the performance requirements,but also satisfy needs of senior vibration and noise level.Mixed flow pump is a kind of vane pump with high efficiency and stable operation.By considering one excessive vibration phenomenon,in this thesis,excitation sources of the main pump are analyzed and simulations results are compared with experimental ones.Based on the simulation,Optimization procedues are also proposed and then checked with measured results.The main contents are as follows:1.Modal characteristics of the pump is studied using finite element and experimental tests: finite element model is updated with the experimental modal data with both resonant frequencies and mode shapes considered.2.Fluent is used to simulate the steady and unsteady state of mixed flow pump,researching the distribution of internal pressure and velocity,the characteristics of pressure pulsations in typical location and the force of the impeller.The results show that the operation of the pump is stable.The blade frequency has largest influence on the pressure pulsation.3.Approximate analytical method and finite element method are used to solve the running electromagnetic force of motor.Among them,the approximate analytical method employ the procedure of magnetic potential multiplying by permeability.FEM is based on Maxwell stress tensor method.Ansoft is used to calculate the electromagnetic force.Finally,the spectral characteristics of the electromagnetic force is analyzed.Results of different methods are also compared.4.By using harmonic response method,the vibration response of the pump is calculated.Results is compared with the experimental ones to verify the correctness of the calculation of excitation force.For this excessive vibration phenomenon,the transmission path of vibration source is optimized by increasing damping and the matching of structure impedance.The experimental results show that the proposed procedures can effectively reduce the level ofvibration.