Research On Vibration And Noise Characteristics Of 25CL-30 Centrifugal Pump

With the rapid development of information technology,the "stealth" of ships has become a hot research topic,and vibration reduction and noise reduction are its core problems.Centrifugal pump is one of the important auxiliary machinery of ships,and its structural parameters are important parameters to study the vibration characteristics of marine centrifugal pump.Therefore,the in-depth study of the structural parameters of centrifugal pump is of great significance to the study of the performance and vibration characteristics of marine centrifugal pump.Firstly,the structural design of25cl-30 centrifugal pump is carried out,and the rationality of the structural parameters of impeller and volute in the design process of centrifugal pump is analyzed.Taking the designed centrifugal pump as the research goal,the performance characteristics of centrifugal pump are calculated by CFD software to obtain the flow field information,pressure pulsation and excitation force in centrifugal pump,so as to provide data basis for the subsequent calculation of vibration characteristics.On this basis,the static,modal and harmonic response of centrifugal pump are analyzed and calculated based on the one-way fluid structure coupling method.Finally,a feasible optimization design scheme is proposed to reduce the vibration of centrifugal pump.The main contents of this paper are as follows:(1)Through the basic parameters of 25cl-30 centrifugal pump,the solid and fluid domain modeling of centrifugal pump is carried out.It includes the selection of structural parameters of impeller and volute.After the solid model is established,the corresponding fluid domain model is obtained through Boolean operation.(2)The performance characteristics of centrifugal pump are analyzed by CFD software.It includes the distribution and change trend of head,efficiency,static torque,pressure field,velocity field,turbulent kinetic energy and cavitation phenomenon,analyzes the influence of fluid velocity and impeller speed on the performance characteristics of centrifugal pump,and calculates the trend of pressure pulsation under rated working condition of centrifugal pump.(3)Different CFD softwares are used to solve the distribution and change trend of centrifugal pump pressure field,which is compared with the previous ones.The equivalent stress and structure deformation of the impeller under different fluid flow and different speed are solved to verify the rationality of the impeller structure.Analyze the modal vibration mode,natural frequency and variation law of dry and wet mode of impeller and centrifugal pump system,and apply the flow field pressure fluctuation as the excitation force to analyze the harmonic response of centrifugal pump to solve its vibration characteristics.(4)The basic methods of time domain and frequency domain analysis and processing of shafting vibration signals are introduced,and the signal acquisition sensors and processing instruments selected for vibration test are studied.The vibration characteristic test of centrifugal pump is designed,and the third octave frequency range and vibration intensity of centrifugal pump are analyzed.The difference between the experimental data and the simulation results proves the correctness of the model and research method in this paper.(5)Using the numerical calculation method to calculate the vibration characteristics of the optimized impeller parameter structure,it is found that the optimization of the impeller results is effective to reduce the vibration characteristics of the centrifugal pump.