Fluctuating Flow behind the Impeller of Centrifugal Pump

抄録

In a volute pump the periodic fluctuation of the velocity and the pressure behind the impeller are one of the major sources of vibration and noise of blade passing frequency. Therefore knowledge on the fluctuating flow behind the impeller is important for the noise reduction of pump. Experimental investigation was performed to detect the flow behind the impeller. Velocity fluctuations are much affected by the viscous wakes and the effects of the viscous wakes increase with a decreasing flow coefficient. Static pressure fluctuations are less affected by viscous wakes and they show good agreement with the predictions by the potential flow theory. Behaviors of the fundamental and harmonics of the fluctuations are also described.