Development And Research Of Low-noise Marine Magnetic Pump

Marine pump is used for pump variable liquids which widely applied on the diverse ships voyaging the sea.With the national development of national defense in recent years,the vibration and noise reducing have became more and more fashionable.In the case that the cavitation phenomena unhappens upon the marine pump,the main noise source comes from three aspects.First,the flow noise caused by the blades which sweep volute generates pressure flucations.Second,the mechanical vibration is caused by the radial force distribution uneven between components.Third,the wind noise caused by fan of classical motor interacts with atmosphere.To solve the noise resource of marine pump,in our school and Jiangsu Zhenhua Pump Industry Cooperation process,the structure of marine pump is optimize innovation,and the prototype of low noise magnetic pump is manufactured.This topic relying on the Development of Low Noise Marine Magnetic Pump(Jiangsu University Project number:20160067).On the basis of summarizing current research at home and abroad,an existing hydraulic was reformed,magnetic transmission way was adopted and the cooling structure into water-cooling in electric motor was changed.In the end,a whole new low noise marine magnetic pump is completely finished.Study on the external characteristic,pressure fluctuation,radial force pulsation,and flow noise by the theoretical arithmetic combined with numerical simulation.The main contents and research results of this paper are as follows:1.In order to reduce flow noise while impeller sweep volute tongue.The impeller with different outlet edges is designed by using the modular conversion methods.Velocity field,pressure field,hydraulic efficiency,head and shaft power were researched and compared.The characteristics among two types of impeller can be used in low noise marine magnetic pump.2.Innovation design for marine pump drive method.For the using magnetic drive method,new structure applied before the prototype was manufactured.The performance of prototype was tested and evaluated.The low noise marine magnetic pump meets design requirements.3.The pressure fluctuation in the low-noise marine magnetic pump were analyzed for both impellers.The numerical simulation results demonstrate that the tilted blade impeller can reduce the characteristics of pressure fluctuation in a certain extent among volute tongue which people care about,where the pressure fluctuation would be significantly enhanced if tilted impeller blade run in the area slightly before the tongue.4.Considering the uneven distribution of the radial force from impeller,this phenomena cause mechanical vibration for casing collision between the impeller and the volute.Two types of impeller were analyzed under the same conditions of different flow rates,the results show that the radial force of change amplitude among impeller with inclined outlet edge is significantly weakened than the impeller with vertical outlet edge,so the mechanical noise level caused by uneven distribution of radial force can be reduced.5.Based on the principle of automotive muffler,the water-cooled cooling chamber(Anechoic Room)around the traditional water-cooled motor was reformed,one types of reactive muffle connected by several small anechoic was designed.The numerical simulation results show that the reformed motor have great effects on reducing the flow noise upon medium-high frequency which caused by blade frequency.However,compared with the low frequency noise caused by the shaft frequency,the originally designed motor is better.Comparing with original motor,the reformed motor have great advantage on cooling capacity but have adverse effect on head loss.