Prediction of Cavitation Evolution and Cavitation Erosion on Centrifugal Pump Blades by the DCM-RNG Method

Abstract

Cavitation can reduce the efficiency and service life of the centrifugal pumps, and a long-term operation under cavitation conditions will cause cavitation damage on the surface of material. The external characteristic test of the IS65-50-174 single-stage centrifugal pump was carried out. Moreover, the cavitation mechanism under specific conditions was analyzed by numerical simulation. Considering the macroscopic cavitation flow structure in the centrifugal pump, three different cavitation erosion prediction methods were used to predict the erodible areas. The results show that the calculation results obtained by the density correction method (DCM) can well match the flow characteristics of the centrifugal pump under the rated conditions. When the centrifugal pump head drops by 3%, cavitation mainly occurs on the suction surface, and the cavity on the pressure surface is mainly concentrated near the front cover. The cavitation prediction method based on the time derivation of pressure change is not suitable for centrifugal pumps, while the prediction result of the erosive power method is more reasonable than the others. At time 0.493114 s, the maximum erosive power appears on the blade near the volute tongue, and its value is 1.46 e − 04 W.

Numerical study on cavitation flow and induced pressure fluctuation characteristics of centrifugal pump

“…In engineering, the point where the head drops by 3% is often taken as the critical point of cavitation to determine the operating range of centrifugal pumps. 16 Therefore, the critical NPSHa of the model pump is 1.57 m.…”

Assessment of Cavitation Erosion in a Water-Jet Pump Based on the Erosive Power Method

“…The cavitation volume is reduced when cavity collapses, and the pressure wave is released. The erosive power function p pot can be defined as [ 25 , 27 – 30 , 33 , 35 , 36 , 40 , 46 ] where p is the pressure surrounding the vapor (Pa), p sat is the saturated vapor pressure (Pa), V vap is the vapor volume (m 3 ), V cell is the volume of the grid (m 3 ), α is the vapor volume fraction, and ε is the threshold.…”

How Non-Governmental-Organization-Built Small-Scale Irrigation Systems Are a Failure in Africa

“…However, the adoption of such a solution requires the replacement of surface pumps with submerged pumps to stop the current descent and ascent of said surface pumps in the wells in order to bring them closer to the free surface of the water. Not only were the surface pumps not suitable, but they would also have broken down as a result of cavitation [27]. In addition, descent/ascent is a hard job, with a risk of falling.…”

“…As mentioned above, these surface pumps should have been replaced by submersible solar pumps to allow for the safe and sustainable pumping of a water table that reached a depth of more than 12 m in the dry season. Pumping groundwater to a depth of more than 6 m leads to the cavitation (destruction of propellers) [27] of the pumps and their destruction (Figure 4). A survey 6 months after the end of the project revealed that 50% of the pumps were broken down.…”