Numerical And Experimental Research On The Flow-noise Of The Centrifugal Pump In The Seawater Pipe

With the advancement of noise reduced technique for power equipment, flow-induced noise in seawater pipe system is very important, and has received more and more attention in recent years. Finding out the source characteristics of noise in pipe system is the basic of reducing noise. As a main acoustic source, the noise generated by centrifugal pump is an important part in pipe system. Thus, numerical simulation and experiment are carried out to study the flow and source characteristics of centrifugal pump in seawater pipe and to provide some help for reducing noise.Firstly, the internal flow characteristics of a certain centrifugal pump is investigated, by simulating the internal flow of it with CFD method and sliding mesh technique. Secondly, test bed is set up with theory of two-port method, and then flow noise in the inlet and outlet are measured and the effect of hydrodynamic parameters on flow-noise is also analyzed. Finally, through dealing with the experiment data, the parameters that describe the source characteristics of centrifugal pump is gained.Results from simulation and experiment under various condition show that flow characteristics in centrifugal pump is very complicated and there have some rules in it, the static pressure gradients and the velocity gradients near the volute tongue is large; the main noise-generating mechanism is assumed to be the interaction of impeller and volute, and hydrodynamic parameters including flow and rotate speed have obvious effect on flow-noise. As an outstanding point of this paper, the two-port method can availably measure the source characteristics of the centrifugal pump, which has important meaning for further research on pump noise and can provide help for control of vibration and noise in pipe system.