Investigating & Improving the Drooping Curve of A Two-Stage Feed Pump
A two-stage between-bearing pump of the upgraded material was supplied to replace the existing machine. The pump utilized a higher number of impeller blades to obtain higher efficiency at its design point, but exhibited a drooping head-flow characteristic during its shop test. Impeller reworks were done to improve the drooping curve. CFD study was carried out to examine the pump flow behavior. A more stringent test procedure using the high sampling frequency was implemented. Judging from the parameter fluctuations and uncertainties, the pump curve was deemed statistically stable. A key lesson learnt from this particular case is not to overly push the efficiency of the pump at a single best efficiency point, but to have a more balanced design between achieving good pump efficiency and attaining a stable curve.
Tzuu Bin, Ng (2018). Investigating & Improving the Drooping Curve of A Two-Stage Feed Pump. Turbomachinery Laboratory, Texas A&M Engineering Experiment Station. Available electronically from