Flow characteristics around a circular cylinder placed horizontally above a plane boundary / Wei-Jung Lin in Journal of engineering mechanics, Vol. 135 N° 7 (Juillet 2009)  

Flow characteristics around a circular cylinder placed horizontally above a plane boundary [texte imprimé] / Wei-Jung Lin, Auteur ; Chang Lin, Auteur ; Shih-Chun Hsieh, Auteur . - pp. 697-716.
Mécanique appliquée
Langues : Anglais (eng)
in Journal of engineering mechanics > Vol. 135 N° 7 (Juillet 2009) . - pp. 697-716

Mots-clés :	Vortex shedding Eddies Cylinders Boundary layers Reynolds number.
Résumé :	Flow characteristics around a circular cylinder positioned near a plane boundary (on which laminar boundary layer flow develops in the absence of circular cylinder), are investigated for Reynolds numbers R ranging from 7.8×102 to 1.15×104. Particle image velocimetry and fiber laser Doppler velocimetry were used to measure the velocity fields and velocity time histories, respectively. Flow structures are particularly revealed using flow visualization technique at R=7.8×102 for gap ratios G/D (where G is the net gap between the surface of circular cylinder and the plane boundary), varying from 0 to 4. Based on the experimental results, the variation of Strouhal number of shedding vortex (or eddy) with G/D, the mechanism of vortex shedding suppression, and the streamwise velocity profiles of the upper shear layers and gap flows for small G/D are all discussed. Although the regular, alternate vortex shedding is suppressed for G/D=4×103, although most of the previous studies indicate that the S is insensitive to G/D, the present study shows that S still increases as G/D decreases but the variations of S are in a small range (i.e., 0.18
DEWEY :	620.1
ISSN :	0733-9399
En ligne :	http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]