Constant-speed oscillation of a pump turbine observed on a pumped-storage model system Hu, J, Yang, J, Zeng, Wei and Yang, J 2019, Constant-speed oscillation of a pump turbine observed on a pumped-storage model system, Journal of Fluids Engineering, Transactions of the ASME, vol. 141, no. 5, pp. 1-13, doi: 10.1115/1.4042763. Title Constant-speed oscillation of a pump turbine observed on a pumped-storage model system Author(s) Hu, J Yang, J Zeng, Wei Yang, J Journal name Journal of Fluids Engineering, Transactions of the ASME Volume number 141 Issue number 5 Article ID ARTN 051109 Start page 1 End page 13 Total pages 13 Publisher American Society of Mechanical Engineers Place of publication New York, N.Y. Publication date 2019-05 ISSN 0098-2202 1528-901X Keyword(s) Engineering Engineering, Mechanical Science & Technology Technology Summary The hydraulic characteristics of pump turbines in off-design conditions, especially the S-shaped characteristics, are crucial for the safety and stability of the unit. To explore the S-characteristics of pump turbines through a transient method, an experimental investigation was conducted based on a pumped-storage model system at Wuhan University. By shutting down the circulating pump, a special transient process was triggered, forcing the pump turbine to operate in turbine mode, turbine brake mode, and reverse rotational pump mode. As the rotational speed of the pump turbine was maintained almost constant in the oscillation process with a maximum deviation of 0.6%, this transient operation was named as constant-speed oscillation (CSO). The parameters for global performance and pressure pulsations in the vaneless gap were measured and analyzed. In addition, the one-dimensional rigid column theory was used to establish a mathematical model for simulation. The results from simulation were quantitatively compared with the experimental results. Finally, the reason for the CSO was theoretically explained based on stability analysis through the established mathematical model. It was observed that the positive slope of ned–Qed characteristic curves at no-flow resulted in this oscillation. In contrast, the simulation was performed under the same conditions with a modified ned–Qed characteristic curve, which had a negative slope at no-flow. However, the results showed that, with the modified characteristic curve, the pump turbine would stabilize at no-flow. Language eng DOI 10.1115/1.4042763 Field of Research 09 Engineering HERDC Research category C1.1 Refereed article in a scholarly journal Persistent URL http://hdl.handle.net/10536/DRO/DU:30164148 Document type: Journal Article Collections: Faculty of Science, Engineering and Built Environment School of Engineering Related Links Link Description Connect to published version Go to link with your DU access privileges   Connect to Elements publication management system Go to link with your DU access privileges     Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved. Versions Version Filter Type Fri, 11 Mar 2022, 07:36:19 EST Fri, 11 Mar 2022, 15:25:27 EST Mon, 02 May 2022, 14:59:17 EST Mon, 09 May 2022, 14:45:59 EST Mon, 09 May 2022, 14:47:22 EST Mon, 09 May 2022, 14:51:30 EST Filtered Full Citation counts:   Cited 7 times in TR Web of Science Cited 8 times in Scopus Search Google Scholar Access Statistics: 10 Abstract Views  -  Detailed Statistics Created: Fri, 11 Mar 2022, 07:36:19 EST