Abstract
Dredge pumps are usually operated at part-load conditions, in which the low-solidity centrifugal impeller could experience large internal energy dissipation, related to flow separation and vortices. In this study, SST k-ω and SAS-SST turbulence models were used, in steady and unsteady simulations, for a low-head centrifugal pump with a three-bladed impeller. The main focus of the present work was to investigate the internal energy dissipation in rotating an impeller at part-load operating conditions, related to flow separation and stall. The unsteady nature of these operating conditions was investigated. Performance experiments and transient wall pressure measurements were conducted for validation. A methodology for internal energy dissipation analysis has been proposed; and the unsteady pressure fluctuations were analyzed in the rotating impeller. The internal power losses in the volute and the impeller were mostly found in the centrifugal pump. The rotating stall phenomenon occurred with flow separation and detachment at the part-load operating condition, leading to a dissipation of the internal energy in the impeller. The rotating impeller experienced pressure fluctuations with low frequencies, at part-load operating conditions, while in the design operating condition only experienced rotating frequency.
Highlights
Low-head centrifugal pumps are widely used in small-scale dredging equipment, for delivering slurry
Since the centrifugal impeller was composed of three blades, steady simulations were conducted
The results were as the results steady on centrifugal pump see
Summary
Low-head centrifugal pumps are widely used in small-scale dredging equipment, for delivering slurry. The centrifugal impellers usually feature three to six blades with a large expansion ratio of the flow passages. Most studies on slurry pumps were conducted on pumps with four to six impeller blades [1]. The asymmetric impeller structure with fewer blades had an important influence on the performance and pressure fluctuation of the pumps. For single-bladed sewage pump, Nishi et al [2] performed numerical simulations and experiments and detected the asymmetric pressure and velocity distribution. Pei et al [3] investigated the uneven distribution of pressure fluctuation intensity in the single-bladed impeller and volute, using the CFD method. Melzer et al [4] studied the transient pressure in the volute, numerically and experimentally
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
