Publication detail
PIV Measurement of Separated Flow in a Square Channel With Streamwise Periodic Ribs on One Wall
HEJČÍK, J. SUNDÉN, B. WANG, L.
Czech title
Měření vlastností separovaného v proudu ve čtvercovém kanále s obdélníkovými žebry
English title
PIV Measurement of Separated Flow in a Square Channel With Streamwise Periodic Ribs on One Wall
Type
journal article - other
Language
en
Original abstract
In this study, particle image velocimetry (PIV) is used to investigate the physical process of separated flow in a square channel roughened with periodically transverse ribs on one wall. The ribs obstruct the channel by 15% of its height and are arranged 12 rib heights apart. The Reynolds number, based on the bulk-mean velocity and the corresponding hydraulic diameter of the channel, is fixed at 22,000. Assuming flow periodicity in the streamwise direction, the investigated domain is between two consecutive ribs. The emphasis of this study is to give some insight into the turbulence mechanism associated with separation, reattachment, and subsequent redevelopment. Results are included for mean velocity, friction coefficient, vorticity thickness, Reynolds shear stress, anisotropy parameter, and production of turbulent kinetic energy and shear stress. Based on the two-point correlation profiles, Taylor microscales are derived to reveal the sizes of the turbulence structure in the longitudinal and lateral directions. Moreover, Galilean decomposition is applied to the instantaneous velocity fields. The result shows that the separated shear layer is dominated by the large-scale, unsteady vortical structures.
Czech abstract
V příspěvku je popsáno využití metod PIV pro výzkum přenosu tepla v separovaném proudu. Separovaný proud vzniká ve čtvercovém kanálu jehož jedna strana je opatřena žebry, která zabírají 15 % výšky kanálu. Výsledky měření, získané při Reynoldsově čísle 22 000, jsou prezentovány a popsány.
English abstract
In this study, particle image velocimetry (PIV) is used to investigate the physical process of separated flow in a square channel roughened with periodically transverse ribs on one wall. The ribs obstruct the channel by 15% of its height and are arranged 12 rib heights apart. The Reynolds number, based on the bulk-mean velocity and the corresponding hydraulic diameter of the channel, is fixed at 22,000. Assuming flow periodicity in the streamwise direction, the investigated domain is between two consecutive ribs. The emphasis of this study is to give some insight into the turbulence mechanism associated with separation, reattachment, and subsequent redevelopment. Results are included for mean velocity, friction coefficient, vorticity thickness, Reynolds shear stress, anisotropy parameter, and production of turbulent kinetic energy and shear stress. Based on the two-point correlation profiles, Taylor microscales are derived to reveal the sizes of the turbulence structure in the longitudinal and lateral directions. Moreover, Galilean decomposition is applied to the instantaneous velocity fields. The result shows that the separated shear layer is dominated by the large-scale, unsteady vortical structures.
Keywords in Czech
Separované proudění, Turbulence, PIV
Keywords in English
Separated Flow, Turbulence Properties, PIV
RIV year
2007
Released
01.07.2007
Publisher
ASME
Location
ASME Technical Publishing Office Three Park Avenue New York NY 10016
ISSN
0098-2202
Journal
JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
Volume
129
Number
7
Pages count
8
BIBTEX
@article{BUT44808,
author="Jiří {Hejčík} and Bengt {Sundén} and Lei {Wang},
title="PIV Measurement of Separated Flow in a Square Channel With Streamwise Periodic Ribs on One Wall",
journal="JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME",
year="2007",
volume="129",
number="7",
month="July",
publisher="ASME",
address="ASME Technical Publishing Office
Three Park Avenue
New York NY 10016",
issn="0098-2202"
}