Results 11 to 20 of about 184,150 (234)
Temporal and Spatial Analysis on the Fractal Characteristics of the Helical Vortex Rope
Fractal and Fractional, 2022 Vortex rope is a common phenomenon in the draft tube of hydraulic turbines. It may cause strong pressure pulsation, noise, and strong vibration of the unit especially when it is helical. Therefore, the study of vortex rope is of great significance.
Ruofu Xiao, Puxi Li
exaly +5 more sources
Research on the Vortex Rope Control Techniques in Draft Tube of Francis Turbines
Energies, 2022 Francis turbines are most widely used in hydropower due to their characteristics which include a fast response and wide time-scale operation. The vortex rope inside Francis turbines is a common flow phenomenon, which always causes strong vibration ...
Peijian Zhou, Chun Xiang
exaly +5 more sources
Application of Computer Graphics Flow Visualization Methods in Vortex Rope Investigations [PDF]
Energies, 2021 Computer graphics visualization techniques for application on data from Computational Fluid Dynamics (CFD) simulations of the vortex rope, a phenomenon present in hydraulic turbines operating in off-design conditions, were devised. This included not only
Ondřej Urban, Pavel Rudolf
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An Overview of Active Control Techniques for Vortex Rope Mitigation in Hydraulic Turbines
Energies, 2023 This review addresses the current state of research into active control and suppression of vortex rope in hydroturbines under off-design operating conditions.
Sergey Skripkin +2 more
exaly +4 more sources
Active flow control of the vortex rope and pressure pulsations in a swirl generator [PDF]
Engineering Applications of Computational Fluid Mechanics, 2017 The vortex rope and pressure pulsations caused by a radial pressure gradient in the conical diffuser of a swirl generator is controlled using continuous slot jets with different momentum fluxes and angles injected from the runner crown.
Ardalan Javadi, Håkan Nilsson
exaly +3 more sources
Applied Sciences (Switzerland), 2021 The flow in a Francis turbine at full load is characterised by the development of an axial vortex rope in the draft tube. The vortex rope often promotes cavitation if the turbine is operated at a sufficiently low Thoma number.
François Avellan +2 more
exaly +3 more sources
Multiscale investigation of cavitation surge characteristics in the swirling flow using Eulerian-Lagrangian method [PDF]
Ultrasonics SonochemistryHydrodynamic cavitation (HC) surge accompanied by strong swirl is widely present in fluid machinery and has become a hot topic in many engineering fields. This paper employed a two-way coupling Eulerian-Lagrangian multiscale cavitation modeling method to
Ziyang Wang +3 more
doaj +2 more sources
Part Load Vortex Rope as a Global Unstable Mode
Journal of Fluids Engineering, 2017 Renewable energy sources (RES) have reached 23.7% of the worldwide electrical generation production in 2015. The hydraulic energy contribution amounts to 16.6% and comes mainly form large-scale hydropower plants, where Francis turbines represents 60% of the generating units. However, the future massive development of RES will require more advanced grid
Pasche, Simon +2 more
openaire +4 more sources
Vortex rope patterns at different load of hydro turbine model [PDF]
MATEC Web of Conferences, 2017 Operation of hydraulic turbines beyond optimal conditions leads to formation of precessing vortex core in a draft tube that generates powerful pressure pulsations in a hydraulic system.
Skripkin Sergey +3 more
doaj +2 more sources
On the upper part load vortex rope in Francis turbine: Experimental investigation [PDF]
IOP Conference Series: Earth and Environmental Science, 2010 The swirling flow developing in Francis turbine draft tube under part load operation leads to pressure fluctuations usually in the range of 0.2 to 0.4 times the runner rotational frequency resulting from the so-called vortex breakdown. For low cavitation number, the flow features a cavitation vortex rope animated with precession motion.
Nicolet, C +3 more
openaire +3 more sources