Publication detail
Vortex Identification in Different Types of Flow
RUDOLF, P.
Czech title
Identifikace vírových struktur v různých typech proudění
English title
Vortex Identification in Different Types of Flow
Type
conference paper
Language
en
Original abstract
Lots of vortex definitions were devised to locate vortex cores and there is no common consensus on the best one. Four vortex identification methods were applied in this paper, namely pressure minimum, vorticity modulus, normalized helicity and Q – criterion for three different types of flow (steady flow in curved channel of rectangular cross-section, unsteady flow in elbow draft tube, unsteady flow over backward facing step). Each criterion has different performance for the particular flow type. But it can be very roughly generalized that pressure minimum is too coarse and and Q-criterion worke best. Finally it must be stressed that threshols specification plays key role for all criteria.
Czech abstract
Bylo vyvinuto mnoho metod pro lokalizaci vírových struktur, ale doposud neexistuje obecná shoda na nejlepsí metodě ani jasná definice vírové struktury. Článek prezentuje aplikaci čtyř kriterií pro vyhledávání vírů: minimum tlaku, maximum vířivosti, normalizovaná helicita a Q- kritérium. Tato jsou aplikována na tři různé druhy proudění: stacionární proudění v zakřiveném kanálu, nestacionární proudění v sací troubě vodní turbíny a a nestacionární proudění kolem zpětného schodu. Každé z kriterií je střídavě úspěšné pro laždý t typů proudění. Lze shrnout, z jistoz mírou zevšeobecnění, že nejlépe víry detekuje Q. krotérium a jako nejhorší se jeví kritrium minima tlaku. Nicméně velkou roli hraje i nastavení citlivosti těchto kriterií.
English abstract
Lots of vortex definitions were devised to locate vortex cores and there is no common consensus on the best one. Four vortex identification methods were applied in this paper, namely pressure minimum, vorticity modulus, normalized helicity and Q – criterion for three different types of flow (steady flow in curved channel of rectangular cross-section, unsteady flow in elbow draft tube, unsteady flow over backward facing step). Each criterion has different performance for the particular flow type. But it can be very roughly generalized that pressure minimum is too coarse and and Q-criterion worke best. Finally it must be stressed that threshols specification plays key role for all criteria.
Keywords in Czech
identifikace víru, kritérium, helicita, vířivost
Keywords in English
vortex identification, criterion, helicity, vorticity
RIV year
2005
Released
16.02.2005
Publisher
Institute of Thermomechanics
Location
Prague
ISBN
80-85918-92-7
Book
Topical Problems of Fluid Mechanics 2005
Edition number
1
Pages count
4
BIBTEX
@inproceedings{BUT18451,
author="Pavel {Rudolf},
title="Vortex Identification in Different Types of Flow",
booktitle="Topical Problems of Fluid Mechanics 2005",
year="2005",
month="February",
publisher="Institute of Thermomechanics",
address="Prague",
isbn="80-85918-92-7"
}