Results 21 to 30 of about 184,150 (234)
Intake Ground Vortex Aerodynamics [PDF]
, 2008 When an aircraft is operating in static or near static conditions during taxiing or take-o a vortex can form between the ground and the intake. With engine diameters increasing, intakes are moving non-dimensionally closer to the ground and as a ...
Murphy, John
core +7 more sources
Vortex rope mitigation with azimuthal perturbations: A numerical study
IOP Conference Series: Earth and Environmental Science, 2021 Abstract A novel method to mitigate the rotating vortex rope is investigated numerically on a propeller turbine using ANSYS CFX. Pulsating momentum is injected in a horizontal plane in the diffuser cone from four evenly spaced jets. Three mitigation strategies are tested; M1 in which the momentum is injected perpendicular to the axial ...
Holmström, H +2 more
openaire +2 more sources
Jump rope vortex in liquid metal convection [PDF]
Proceedings of the National Academy of Sciences, 2018 Significance The large-scale circulation (LSC) is the key dynamical feature of turbulent thermal convection. It is the underlying structure that shapes the appearance of geo- and astrophysical systems, such as the solar granulation or cloud streets, and the cornerstone of theoretical models. Our laboratory-numerical experiments reveal
Tobias Vogt +3 more
openaire +6 more sources
Energies, 2021 The inter-blade passage vortex, the vortex rope of the draft tube, and the vortex in the guide apparatus are the characteristics of flow instability of the Francis turbine, which may lead to fatigue failure in serious cases.
Tao Guo, Lihui Xu, Wenquan Wang
doaj +1 more source
Machines, 2022 The flow characteristics of the draft tube of a Francis turbine have a significant influence on turbine stability. Numerical simulations were performed for a Francis turbine under three different output conditions of 20%, 100%, and 120% at the rated and ...
Lei Ji +7 more
doaj +1 more source
Manipulation of the swirling flow instability in hydraulic turbine diffuser by different methods of water injection [PDF]
EPJ Web of Conferences, 2018 Vortex rope, which induces substantial pressure pulsations, arises in the draft tube (diffuser) of Francis turbine for off-design operating conditions.
Rudolf Pavel +3 more
doaj +2 more sources
Hydraulic Vibration and Possible Exciting Sources Analysis in a Hydropower System
Applied Sciences, 2021 To understand the hydraulic vibration characteristics in a traditional hydropower system and identify possible exciting sources that may induce serious hydraulic vibrations in the flow passage, experimental tests and numerical calculations were conducted
Aili Shen +5 more
doaj +1 more source
Energies, 2022 The vortex rope in the draft tube is considered as the major contributor to pressure pulsation at partial load (PL) conditions, which causes the hydro unit to operate unstably.
Zhumei Luo +4 more
doaj +1 more source
Machines, 2023 The existence of vortex ropes inside the draft tube significantly impacts hydraulic efficiency and operational stability, and few studies on the formation mechanism of vortex ropes and hydraulic loss problems have been explored.
Haobo Wang +3 more
doaj +1 more source
On the Rotating Vortex Rope and Its Induced Structural Response in a Kaplan Turbine Model
Energies, 2022 The rotating vortex rope, which can be decomposed in the rotating and the plunging modes, is the origin of pressure fluctuations in the draft tube cone when hydraulic turbines operate at part load, compromising the structural integrity and limiting the output load.
Rafel Roig +4 more
openaire +4 more sources