CHARACTERIZATION OF BLADE-PASSING FREQUENCY SOUND SOURCES IN A CENTRIFUGAL PUMP FROM PRESSURE FLUCTUATION MEASUREMENTS

摘要

Rotor-stator interaction in centrifugal pumps and fans produces fluid-dynamic excitation at the blade-passing frequency that, depending on the operating point of the machine, can generate acoustic pressure waves of big amplitude. In order to quantify the effect of that fluid-dynamic interaction on the generation of noise, a simple acoustic model has been proposed for the volute, in which a number of ideal point sources are located at some position in the volute. These ideal sources are assumed to radiate plane sound waves along the volute at the blade-passing frequency towards both the positive and negative directions. The characteristics of the point sources and other model parameters are to be established for each pump and flow condition by comparison with available experimental data of pressure fluctuations, on a least square-error basis. This paper shows the procedure for determination of the ideal sound sources properties and the results obtained when applying the method to a centrifugal pump previously tested under a variety of flow-rates.