Experimental Investigation on the Effect of the Staggered Impeller on the Unsteady Pressure Pulsations Characteristic in a Pump

Abstract

High−energy pressure pulsation induced by rotor−stator interaction (RSI) is the primary source of flow−induced vibration noise in the pump, affecting the pump’s stability and system operation. In order to find an effective method to suppress the pressure pulsation in the pump caused by RSI, a new staggered impeller is proposed in this paper, which can significantly suppress the pressure pulsation energy. The unsteady pressure pulsation characteristic of the original impeller and the staggered impeller scheme are measured and analyzed under different working flow conditions. The results show that although the hydraulic performance of the model pump decreases to a certain extent when the staggered impeller is used, the pressure pulsation energy in the pump decreases significantly. Under 0.8QN–1.2QN working flow conditions, the energy suppression effect of the blade passing frequency (fbpf) amplitude is higher than 80% with the staggered impeller scheme. The Root Mean Square (RMS) values for distribution of pressure pulsation in different frequency bands varies greatly, and the pressure pulsation energy near the tongue is prominent. On a broader frequency band (0–6 fbpf), the pressure pulsation energy of the staggered impeller scheme is smaller than that of the original impeller scheme. With the expansion of the frequency band, the pressure pulsation energy decreased steadily, with a minimum decrease of 37.33%.

Keywords

• centrifugal pump
• staggered impeller
• unsteady pressure pulsation
• experimental investigation
• pressure pulsation suppression