Publication detail
Mitigation of swirling flow with a vortex rope by passive installations—Theory, simulations, and experiments
URBAN, O. KURKOVÁ, M. POCHYLÝ, F.
Czech title
Potlačení vířivého proudění s vírovým copem pomocí pasivních zařízení - teorie, simulace a experimenty
English title
Mitigation of swirling flow with a vortex rope by passive installations—Theory, simulations, and experiments
Type
journal article in Web of Science
Language
en
Original abstract
This work is focused on reduction of swirling in cases from hydraulic machinery and, thus, mitigation of instabilities associated with swirling flow. We study this problem analytically using the torque integral equation, numerically using computational fluid dynamics (CFD) simulations, and experimentally using a swirl generator that generates swirling flow approximating that in a draft tube of a hydro turbine operating at a part load, featuring an unsteady spiral vortex—the vortex rope. The analytical description elucidates the effect of different installations on the circumferential velocity. Unconventional conical perforated installations targeting at increasing the dissipation were proposed and tested. The rather unsatisfactory results led to proposing fins placed unconventionally away from the wall, closer to the diffuser axis, which were subsequently shown to be able to reliably suppress the unsteady vortex rope. Their effect is documented by an analysis of CFD results including the proper orthogonal decomposition as well as experimental observations and measurements.
English abstract
This work is focused on reduction of swirling in cases from hydraulic machinery and, thus, mitigation of instabilities associated with swirling flow. We study this problem analytically using the torque integral equation, numerically using computational fluid dynamics (CFD) simulations, and experimentally using a swirl generator that generates swirling flow approximating that in a draft tube of a hydro turbine operating at a part load, featuring an unsteady spiral vortex—the vortex rope. The analytical description elucidates the effect of different installations on the circumferential velocity. Unconventional conical perforated installations targeting at increasing the dissipation were proposed and tested. The rather unsatisfactory results led to proposing fins placed unconventionally away from the wall, closer to the diffuser axis, which were subsequently shown to be able to reliably suppress the unsteady vortex rope. Their effect is documented by an analysis of CFD results including the proper orthogonal decomposition as well as experimental observations and measurements.
Keywords in English
swirling flow; vortex rope; passive flow control
Released
22.12.2022
Publisher
AIP Publishing
ISSN
1070-6631
Volume
34
Number
12
Pages from–to
1–18
Pages count
18
BIBTEX
@article{BUT182717,
author="Pavel {Rudolf} and Ondřej {Urban} and Michaela {Kurková} and František {Pochylý},
title="Mitigation of swirling flow with a vortex rope by passive installations—Theory, simulations, and experiments",
year="2022",
volume="34",
number="12",
month="December",
pages="1--18",
publisher="AIP Publishing",
issn="1070-6631"
}