Dynamics of the Tip Vortices in the Wake Behind a Circular Cylinder of Finite Length

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F20%3A00536291" target="_blank" >RIV/61388998:_____/20:00536291 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/49777513:23210/20:43960358

Výsledek na webu

<a href="https://www.matec-conferences.org/articles/matecconf/pdf/2020/24/matecconf_aenmfme2020_05008.pdf" target="_blank" >https://www.matec-conferences.org/articles/matecconf/pdf/2020/24/matecconf_aenmfme2020_05008.pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/matecconf/202032805008" target="_blank" >10.1051/matecconf/202032805008</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Dynamics of the Tip Vortices in the Wake Behind a Circular Cylinder of Finite Length

Popis výsledku v původním jazyce

The dynamics of the tip vortices in the wake behind a wall-mounted finite-length circular cylinder of the aspect ratio 2 was studied experimentally using time resolved stereo PIV technique. The cylinder was mounted normal to a ground plane and it was subjected to a cross-flow with thin boundary layer developed on the wall, the Reynolds number based on inflow velocity and cylinder diameter was 9.7 thousands. The dynamics of tip vortices were analysed using the POD method applied to the plane perpendicular to the flow close to the cylinder. Besides the decaying power spectrum, slower that the Kolmogorov-type one, the two distinct frequencies were detected on Strouhal numbers 0.09 and 0.15. These frequencies could be linked to the vortical structures dynamics in the wake. The frequency Sh = 0.15 corresponds to predominantly spanwise vortices dynamics with anti-symmetrical patterns with respect to the cylinder axis, while the frequency Sh = 0.09 corresponds to mainly streamwise vortical structures dynamics with symmetrical patterns respectively. Thus, the von Kármán vortex street was detected on Strouhal frequency 0.15.

Název v anglickém jazyce

Dynamics of the Tip Vortices in the Wake Behind a Circular Cylinder of Finite Length

Popis výsledku anglicky

The dynamics of the tip vortices in the wake behind a wall-mounted finite-length circular cylinder of the aspect ratio 2 was studied experimentally using time resolved stereo PIV technique. The cylinder was mounted normal to a ground plane and it was subjected to a cross-flow with thin boundary layer developed on the wall, the Reynolds number based on inflow velocity and cylinder diameter was 9.7 thousands. The dynamics of tip vortices were analysed using the POD method applied to the plane perpendicular to the flow close to the cylinder. Besides the decaying power spectrum, slower that the Kolmogorov-type one, the two distinct frequencies were detected on Strouhal numbers 0.09 and 0.15. These frequencies could be linked to the vortical structures dynamics in the wake. The frequency Sh = 0.15 corresponds to predominantly spanwise vortices dynamics with anti-symmetrical patterns with respect to the cylinder axis, while the frequency Sh = 0.09 corresponds to mainly streamwise vortical structures dynamics with symmetrical patterns respectively. Thus, the von Kármán vortex street was detected on Strouhal frequency 0.15.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20302 - Applied mechanics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

MATEC Web of Conferences

ISBN

—

ISSN

2261-236X

e-ISSN

—

Počet stran výsledku

10

Strana od-do

05008

Název nakladatele

EDP Sciences

Místo vydání

Grenoble

Místo konání akce

Piešťany

Datum konání akce

7. 10. 2020

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

—