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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/23886
Title: Comparison of axial water and air injections in the draft tube of a francis turbine for rvr mitigation
Authors: Khullar S.
Singh, Krishna Mohan
Cervantes M.J.
Gandhi, Bhupendra K.
Published in: American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM
ASME 2021 Fluids Engineering Division Summer Meeting, FEDSM 2021
Abstract: The presence of excessive swirl at the runner outlet in Francis turbines operating at part load leads to the development of flow instabilities such as the rotating vortex rope (RVR). The presence of RVR causes severe pressure pulsations, power swings, and fatigue damage in the turbine unit. Air and water injection in the draft tube have been reported to reduce the detrimental effects of RVR formation in the Francis turbines. Air injection is one of the oldest and most widely used methods. In contrast, water jet injection is a relatively new methodology. The present work reports the numerical simulations performed to compare the respective effectiveness of these methods to mitigate the RVR and the related flow instabilities. The efficacy of the two methods has been compared based on the pressure pulsations and pressure recovery in the draft tube cone. The results show that the air and water injection influence the draft tube flow field in different ways. Both air and water injection led to a reduction in pressure pulsation magnitudes in the draft tube cone. However, the air injection led to a negative pressure recovery while the water injection improved the draft tube action. © 2021 American Society of Mechanical Engineers (ASME). All rights reserved.
Citation: American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM (2021), 2
URI: https://doi.org/10.1115/FEDSM2021-65503
http://repository.iitr.ac.in/handle/123456789/23886
Issue Date: 2021
Publisher: American Society of Mechanical Engineers (ASME)
Keywords: Francis turbines
Hydraulic motors
Tubes (components)
Air injection
Draft tubes
Flow instabilities
Part load
Power swings
Pressure pulsation
Pressure recovery
Rotating vortex
Turbine unit
Vortex rope
Numerical methods
ISBN: 9.78E+12
ISSN: 8888116
Author Scopus IDs: 57216653256
24308174000
55328928400
7006087147
Author Affiliations: Khullar, S., Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
Singh, K.M., Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
Cervantes, M.J., Division of Fluid and Experimental Mechanics, Department of Engineering Sciences and Mathematics LTU, Sweden
Gandhi, B.K., Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
Funding Details: The first author gratefully acknowledges the financial support from IIT-Roorkee through MHRD research fellowship. We would like to show our gratitude to the Central Power Research Institute (CPRI), India, for providing financial assistance to this project under grant no. CPR-1133-MID. The authors are also thankful to Bharat Heavy Electrical Limited (BHEL), India, for sharing the details of turbine design. Ministry of Education, India, MoE; Central Power Research Institute, CPRI: CPR-1133-MID
Corresponding Author: Singh, K.M.; Department of Mechanical and Industrial Engineering, India; email: singhfme@iitr.ac.in
Appears in Collections:Conference Publications [ME]

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