Research On The Vibration And Noise Characteristics Of Marine Pump Unit

The research was carried out under the support of the Zhenjiang Key Research and Development Program(GY2017001)and the project “Low Noise Manufacturing Technical Service of Vane Pump”(20190383)hosted by China Shipbuilding Industry Corporation 719.Marine pump is an important mechanical equipment with many kinds and quantities on modern ships.According to incomplete statistics,among all kinds of auxiliary mechanical equipment except the main engine on the ship,the total number of Marine pumps of various types and different uses accounts for about 20%-30% of the total amount of Marine mechanical equipment.However it generates a lot of vibration and noise during operation.At present,the design of Marine pump with low vibration and low noise has become an urgent requirement.The current study of Marine pump unit vibration and noise problems still exist many problems,for the unit vibration,yet sources and ways for fluid induced vibration still lack of in-depth study,and most scholars have ignored the vibration of the motor.For unit noise,fluid-induced noise is considered as the main source of pump unit noise.However,the current study lacks the recognition of noise sources with different properties under the coupling of sound field and structure field and its contribution in the internal and external fields.This article combinates the numerical calculation and experimental verification to analysis the different excitation source how to influence the vibration noise,And then capture the main vibration and noise.we also explore the dynamic and static clearance parameters of the flow surface roughness on main vibration and noise of the unit,in order to provide a theoretical basis for the evaluation of vibration and noise reduction of Marine pump and its optimized quality.The main work and creative results are as follows:Systematically summarized the domestic and foreign research progress of the pump vibration and noise,in view of the advantages and disadvantages of the numerical calculation methods and application of the Marine pump vibration and noise,we determined the appropriate solution method for Marine pump unit vibration and noise,and the influence of the key dynamic parameters of the gap and wall roughness on pump performance at domestic and abroad is summarized.Based on the problems in the present research,the design and of key parameters research ideas are determined.2.The source characteristics of fluid-induced vibration excitation source and electromagnetic vibration excitation source are systematically analyzed to reveal the frequency spectrum characteristics of vibration generated by different excitation sources and their contribution to the vibration.The results show that the main frequency of fluid-induced vibration is at 295 Hz and the main frequency of electromagnetic vibration is at 100 Hz.Compare the total vibration velocity level of excitation source,and found that the fluid excitation vibration on the inner surface of the pump is larger than the electromagnetic excitation vibration,and the impeller fluid excitation occupies the smallest proportion.3.We established the noise analysis model of internal and external field of Marine pump,and obtained the spectrum characteristics of internal field noise and the distribution of external sound field of different excitation sources by using the method of acoustic-vibration.Morever we compared the contributions of different excitation sources.The results show that the main frequency of the inner field noise generated by different excitation is at the blade frequency,and the flow excited noise generated by the fluid excited shell vibration is less than the flow excited noise induced by the dipole acoustic excitation.In the external field,the main frequency of noise generated by different excitations is still located at the blade frequency,However,the radiation noise induced by the fluid excited shell vibration is dominant.4.we designed base circle diameters and tongue angels under the guarantee of the constant hydraulic performance.in contrast to the influence of the flow characteristics and the main vibration noise of marine pump.The results show that the flow will more uniformin in the volute when properly increasing the base circle diameter,the outlet pressure pulsation and the main vibration and noise sources are present the declining trend.with the increase of the tongue angels,The flow velocity in the impeller is stable,but there is no obvious trend to optimize the flow pattern,the main vibration source presents downward trend after first increases,the main noise sources are first decrease then increase.5.The effects of different roughness of the wall on the flow characteristics and the main vibration noise sources of the Marine pump are compared.The results show that the head and efficiency of Marine pump decreases linearly with the increase of roughness,and the vibration of the pump continues to rise,and the in-flow noise increases first and then decreases.