Abstract
Water passes freely through a hydraulic turbine in the absence of power requirements or during maintenance of the transmission lines, spillways, or dam. Moreover, the turbine operates under no-load conditions prior to generator synchronization during startup and after the generator disconnection from the grid load for shutdown. High-velocity swirling flow during spin-no-load (SNL) induces unsteady pressure pulsations in the turbine, and these pulsations cause fatigue in the blades. To investigate the amplitude of unsteady pressure loading, transient pressure measurements were carried out in a model Francis turbine during SNL. A total of six pressure sensors were mounted inside the turbine, i.e., one in the vaneless space, three on the blade surfaces, and two in the draft tube, and three discharge conditions were investigated over the operating range of the turbine. Analysis of the unsteady pressure data showed that the runner blades experience high-amplitude pressure loading during SNL. The amplitudes at all sensor locations were high compared with those under the normal operating condition of the turbine, i.e., the best efficiency point (BEP), and increased as the discharge through the turbine increased.
Sign-in/Register to access full text options 
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.
