Results 21 to 30 of about 9,992 (233)
Effect of Fins on the Internal Flow Characteristics in the Draft Tube of a Francis Turbine Model
Energies, 2020 Undesirable flow phenomena in Francis turbines are caused by pressure fluctuations induced under conditions of low flow rate; the resulting vortex ropes with precession in the draft tube (DT) can degrade performance and increase the instability of ...
Seung-Jun Kim +6 more
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Machines, 2022 Small vessels operating in coastal waters are susceptible to propeller failure because of the entanglement of marine debris. Secondary accidents such as the injury of divers may also occur when removing entangling material.
Antony John Nyongesa +8 more
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Diffuser Shape Optimization Using Adjoint Solver [PDF]
MATEC Web of ConferencesShape optimization of a diffuser with vortex generator on the inlet that mimics the impeller of a Francis turbine was performed. The optimization is based on the use of the adjoint solver in ANSYS Fluent.
Pham Jakub, Rudolf Pavel
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Coupling Mechanisms Between Vortex Rope Evolution and Cavitation Within the Draft Tube of Pump-turbines [PDF]
Journal of Applied Fluid MechanicsA technique integrating numerical simulations with experimental observations was hereby employed to elucidate the flow instability mechanisms during transient processes in pump-turbines, and a reversible pump-turbine was investigated for in-depth ...
L. Xin, Q. Li, S. Zhang
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Effective low-energy theory of superconductivity in carbon nanotube ropes [PDF]
, 2004 We derive and analyze the low-energy theory of superconductivity in carbon nanotube ropes. A rope is modelled as an array of metallic nanotubes, taking into account phonon-mediated as well as Coulomb interactions, and arbitrary Cooper pair hopping ...
De Martino, A., Egger, R.
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Damping force of air acting on vibrating elevator rope
Mechanical Engineering Journal, 2021 This paper describes the vibration damping characteristics of elevator ropes acted on by air. High-rise buildings sometimes resonate during earthquakes, and the elevator ropes in the building may swing significantly as a result. The vibration analysis of
Raichi TAKUMI, Hideo UTSUNO
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Geophysical Research Letters, 2023 Two types of filamentary currents (FCs) were observed inside a magnetic flux rope at the magnetopause by the Magnetospheric Multiscale mission. The first FC is identified as an electron vortex, while the other is a reconnecting current sheet.
Shimou Wang +6 more
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Images of vortex ropes could improve hydraulic machinery safety
Scilight, 2021 Researchers analyzed the generation and transformation of cavitation vortex ropes with high resolution images.
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Hydroelectric System Response to Part Load Vortex Rope Excitation
IOP Conference Series: Earth and Environmental Science, 2016 The prediction of pressure and output power fluctuations amplitudes on Francis turbine prototype is a challenge for hydro-equipment industry since it is subjected to guarantees to ensure smooth and reliable operation of the hydro units. The European FP7 research project Hyperbole aims to setup a methodology to transpose the pressure fluctuations ...
S Alligné +5 more
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Superconductivity in ropes of carbon nanotubes [PDF]
, 2004 Recent experimental and theoretical results on intrinsic superconductivity in ropes of single-wall carbon nanotubes are reviewed and compared. We find strong experimental evidence for superconductivity when the distance between the normal electrodes is ...
Bouchiat, H. +6 more
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