Influence of rotating speed on tip leakage vortex in a mixed flow pump as turbine at pump mode. (December 2020)

• Record Type: Journal Article
• Authors: Han, Yadong; Tan, Lei
• Is Part Of: Renewable energy. Volume 162(2021)
• Page Start: 144
• Page End: 150
• Publication Date: 2020-12
• Subjects: Mixed flow pump -- Rotating speed -- Tip clearance -- Tip leakage vortex -- Pressure fluctuation; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2020.08.033
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Tip clearance results in tip leakage flow from blade pressure side to suction side, and further deteriorates the energy performance and operation stability. In the present work, the influence of rotating speed on tip leakage vortex in a mixed flow pump as turbine at pump mode is investigated. As rotating speed increases, the pump head increases according to the similarity law and the best efficiency point shifts towards large flow rate. Meanwhile, the tip leakage flow and axial momentum also increase. A prediction model for separation angle of tip leakage vortex is proposed, and its relative error is below 5%. As rotating speed increases, the oscillating frequency of primary tip leakage vortex increases from 201.92 Hz to 215.60Hz, and the high pressure fluctuation region develops from leading edge to nearly the whole blade-to-blade passage. Highlights: Influence of rotating speed on tip leakage vortex in a mixed flow pump is investigated. A prediction model for separation angle of tip leakage vortex is proposed, and the relative error is below 5%. Oscillating frequency of primary tip leakage vortex increases from 201.92 Hz to 215.60Hz as rotating speed increases. High pressure fluctuation region expands from leading edge to the impeller passage as rotating speed increases.