Results 181 to 190 of about 441 (221)

Spatio-temporal evolution mechanism of cavitation vortex ropes in a swirling flow

Physics of Fluids, 2021
Cavitation vortex rope widely occurs in hydraulic machinery, leading to the decrease in performance characteristic and increase in pressure fluctuation. The objective of this study was to explore the generation and transformation of cavitation vortex ropes in a swirling flow.
Deyou Li, Zhipeng Ren, Liang Yu, Qi Yang, Hongjie Wang   +4 more
openaire   +1 more source

Numerical Simulation of the Rotating Vortex Rope with Code_Saturne

2019 International Conference on ENERGY and ENVIRONMENT (CIEM), 2019
The paper presents numerical simulations of the rotating vortex rope (RVR) inside a Francis turbine draft tube. The computational fluid dynamics (CFD) calculations were carried out using the Code_Saturne software. The geometry of the turbine was obtained from the Francis-99 workshops. The mesh files provided for the Francis-99 workshop II were modified
Robert Mitrut, Diana Maria Bucur, Georgiana Dunca, Michel J. Cervantes   +3 more
openaire   +1 more source

Computational analysis of vortex rope in a hydroturbine of Tucuruí dam

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2020
There is a relevant hydraulic potential in Amazon rivers, from which it is generated most of the energy available for the largest part of Brazil. One of the most important hydropower plants in the Amazon is Tucurui dam, which can produce 8370 MW through Francis turbines.
Giordane J. Antunes Junior, Adry K. F. Lima, Jerson R. P. Vaz, Erb F. Lins   +3 more
openaire   +1 more source

Vortex Rope Formation in a High Head Model Francis Turbine

Journal of Fluids Engineering, 2017
Francis turbine working at off-design operating condition experiences high swirling flow at the runner outlet. In the present study, a high head model Francis turbine was experimentally investigated during load rejection, i.e., best efficiency point (BEP) to part load (PL), to detect the physical mechanism that lies in the formation of vortex rope. For
Rahul Goyal, Michel J. Cervantes, B. K. Gandhi   +2 more
openaire   +1 more source

Optimal Control of Part Load Vortex Rope in Francis Turbines

Journal of Fluids Engineering, 2019
The mitigation of the precessing vortex core developing in the draft tube of Francis turbines operating under part load conditions is crucial to increase the operation flexibility of these hydraulic machines to balance the massive power production of intermittent energy sources.
Simon Pasche, François Avellan, François Gallaire   +2 more
openaire   +1 more source

Simulations and Measurements of Pressure Oscillations Caused by Vortex Ropes

Journal of Fluids Engineering, 2006
Pressure oscillations caused by vortex rope were measured in the draft tube of a prototype Francis turbine. The three-dimensional, unsteady Reynolds-averaged Navier-Stokes equations with the RNG κ−ϵ turbulence model were solved to model the flow within the entire flow path of the prototype hydraulic unit including the guide vanes, the runner, and the ...
Zhengwei Wang, Lingjiu Zhou
openaire   +1 more source

Two-Dimensional Numerical Simulation of Vortex Shedding of Multiple Stranded Ropes

Volume 9: Rodney Eatock Taylor Honoring Symposium on Marine and Offshore Hydrodynamics; Takeshi Kinoshita Honoring Symposium on Offshore Technology, 2019
Abstract The stranded rope is one of the important components of the fishery aquaculture equipment. We investigate the fluid flow through two-dimensional stranded rope by direct simulation of the Navier-Stokes equations. We show that for different kinds of stranded rope structures, there are significant differences in hydrodynamic ...
Xinxin Wang, Liuyi Huang, Yanli Tang, Fenfang Zhao, Peng Sun   +4 more
openaire   +1 more source

Model for Vortex Rope Dynamics in Francis Turbine Outlet

1996
The present communication deals with the simulation of the vortex rope present in the outlet of a Francis turbine when operating at partial load regimes This approach is not devoted to the analysis of a complete turbomachinery system but rather to develop a rigorous mathematical analysis for a local phenomenon of practical relevance, We synthesise the ...
G. Pedrizzetti, G. Angelico
openaire   +1 more source

Numerical Analysis of Pulsating Water Jet Method for Mitigating the Vortex Rope

2019 International Conference on ENERGY and ENVIRONMENT (CIEM), 2019
Hydraulic machines, that operate at part load can suffer severe pressure fluctuations. These fluctuations vary in frequency and amplitude depending on the operating point. The cause of these changes in fluctuations, such as a 70% flow rate regime, is the appearance of the rotating vortex (vortex rope). Removing the rotating vortex is a problem that has
Constantin Tanasa, Adrian Stuparu, Alin Bosioc, Romeo Susan-Resiga   +3 more
openaire   +1 more source

Flow-Feedback Method for Mitigating the Vortex Rope in Decelerated Swirling Flows

Journal of Fluids Engineering, 2013
When reaction hydraulic turbines are operated far from the design operating regime, particularly at partial discharge, swirling flow instability is developed downstream of the runner, in the discharge cone, with a precessing helical vortex and its associated severe pressure fluctuations. Bosioc et al.
Constantin Tănasă, Romeo Susan-Resiga, Sebastian Muntean, Alin Ilie Bosioc   +3 more
openaire   +1 more source