The Measured Flow at the Inlet of a Francis Turbine Runner Operating in Speed No-Load ConditionSource: Journal of Fluids Engineering:;2024:;volume( 146 ):;issue: 011::page 111203-1DOI: 10.1115/1.4065384Publisher: The American Society of Mechanical Engineers (ASME)
Abstract: For Francis turbines, speed-no-load (SNL) represents one of the most detrimental operating conditions, marked by significant pressure and strain fluctuations on the runner. Mitigating these fluctuations necessitates a comprehensive understanding and characterization of the flow phenomena responsible for their generation. This paper presents an experimental investigation of the flow at the inlet of a Francis turbine runner model operating in speed-no-load condition using high-speed stereoscopic and endoscopic particle image velocimetry (PIV). The measurements are made in a radial-azimuthal plane that covers the vaneless space and a large region in the interblade channel. This study marks the first-time measurement of critical flow phenomena at this operating point, performed in the runner. Instantaneous and average velocity fields are analyzed, along with other statistical data. The results not only confirm the stochastic nature of the flow at speed-no-load but also highlight the general structure of the flow observed in other studies. The high velocity fluctuations on the suction side are associated with a backflow extending into the vaneless space and a circulation zone occasionally generated by this backflow. Both phenomena are frequently present, but fluctuate stochastically. Additionally, two other circulation zones intermittently form on the pressure side of the blades. The presence of vortices, smaller than the circulation zones, near the blade's leading edge correlates with the backflow intensity.
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contributor author | Rezavand Hesari, Araz | |
contributor author | Munoz, Anthony | |
contributor author | Coulaud, Maxime | |
contributor author | Houde, Sébastien | |
contributor author | Maciel, Yvan | |
date accessioned | 2025-04-21T10:35:49Z | |
date available | 2025-04-21T10:35:49Z | |
date copyright | 5/20/2024 12:00:00 AM | |
date issued | 2024 | |
identifier issn | 0098-2202 | |
identifier other | fe_146_11_111203.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4306519 | |
description abstract | For Francis turbines, speed-no-load (SNL) represents one of the most detrimental operating conditions, marked by significant pressure and strain fluctuations on the runner. Mitigating these fluctuations necessitates a comprehensive understanding and characterization of the flow phenomena responsible for their generation. This paper presents an experimental investigation of the flow at the inlet of a Francis turbine runner model operating in speed-no-load condition using high-speed stereoscopic and endoscopic particle image velocimetry (PIV). The measurements are made in a radial-azimuthal plane that covers the vaneless space and a large region in the interblade channel. This study marks the first-time measurement of critical flow phenomena at this operating point, performed in the runner. Instantaneous and average velocity fields are analyzed, along with other statistical data. The results not only confirm the stochastic nature of the flow at speed-no-load but also highlight the general structure of the flow observed in other studies. The high velocity fluctuations on the suction side are associated with a backflow extending into the vaneless space and a circulation zone occasionally generated by this backflow. Both phenomena are frequently present, but fluctuate stochastically. Additionally, two other circulation zones intermittently form on the pressure side of the blades. The presence of vortices, smaller than the circulation zones, near the blade's leading edge correlates with the backflow intensity. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | The Measured Flow at the Inlet of a Francis Turbine Runner Operating in Speed No-Load Condition | |
type | Journal Paper | |
journal volume | 146 | |
journal issue | 11 | |
journal title | Journal of Fluids Engineering | |
identifier doi | 10.1115/1.4065384 | |
journal fristpage | 111203-1 | |
journal lastpage | 111203-12 | |
page | 12 | |
tree | Journal of Fluids Engineering:;2024:;volume( 146 ):;issue: 011 | |
contenttype | Fulltext |