Maximum suction lift of water jet pumps

摘要

This paper describes an experimental study on water jet pumps with different diameters and nozzle-to-throat area ratios. The results revealed that the area ratio was an important parameter to characterize the maximum suction lift of the jet pumps, while their diameters had a negligible effect. All jet pumps reached the cavitation regime at a suction lift of about 8 mH_2O. In the non-cavitating region, it was found that the higher the area ratio, the higher the maximum suction lift for the same motive pressure head. However, the lower the area ratio, the higher the resistance to enter the cavitation regime. A dimensionless correlation was obtained for the non-cavitating region to describe the maximum suction lift as a function of a modified Thoma number and the area ratio. Curve fitting of experimental data also provided a dimensionless correlation to predict the onset of cavitation. Finally, applications of the results are presented.