Influence of surface roughness on the wake structure of a circular cylinder at Reynolds number 5×10³ to 12×10³

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F22%3A00559027" target="_blank" >RIV/61388998:_____/22:00559027 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378297:_____/22:00559027 RIV/49777513:23210/22:43966464

Výsledek na webu

<a href="https://doi.org/10.1016/j.euromechflu.2022.06.003" target="_blank" >https://doi.org/10.1016/j.euromechflu.2022.06.003</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.euromechflu.2022.06.003" target="_blank" >10.1016/j.euromechflu.2022.06.003</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Influence of surface roughness on the wake structure of a circular cylinder at Reynolds number 5×10³ to 12×10³

Popis výsledku v původním jazyce

The flow around roughened circular cylinders and the wake behind them were studied in a wind tunnel flow using the Particle Image Velocimetry (PIV) method. The Reynolds number ranged from 5140 to 11800, and the real diameter of the cylinders including surface roughness ranged from 15.06 to 17.34 mm. The flow properties and forces around the roughened cylinders was evaluated by means of Strouhal number and coefficient of drag. The wake was analysed by means of mean velocities along the cylinder centreline, its width and the Proper Orthogonal Decomposition (POD) method. The addednsurface roughness was found to decrease the wake length and increase the wake width at lower Reynolds numbers. At higher Reynolds numbers, the added surface roughness did not decrease the wake length, but did increase the wake width, although with less effect. The POD analysis showed changes in the higher modes of the flow. The kinetic energy of the first two modes covers up to 50% of the total kinetic energy - the first two modes in the case of the smooth cylinder have the lowest kinetic energy, whereas the first two modes in the case of the roughest cylinder have the highest kinetic energy. The similarity between the POD modes of the smooth and roughened cylinders might be due the fact that the actual Reynolds number range was below the transitional one.

Název v anglickém jazyce

Influence of surface roughness on the wake structure of a circular cylinder at Reynolds number 5×10³ to 12×10³

Popis výsledku anglicky

The flow around roughened circular cylinders and the wake behind them were studied in a wind tunnel flow using the Particle Image Velocimetry (PIV) method. The Reynolds number ranged from 5140 to 11800, and the real diameter of the cylinders including surface roughness ranged from 15.06 to 17.34 mm. The flow properties and forces around the roughened cylinders was evaluated by means of Strouhal number and coefficient of drag. The wake was analysed by means of mean velocities along the cylinder centreline, its width and the Proper Orthogonal Decomposition (POD) method. The addednsurface roughness was found to decrease the wake length and increase the wake width at lower Reynolds numbers. At higher Reynolds numbers, the added surface roughness did not decrease the wake length, but did increase the wake width, although with less effect. The POD analysis showed changes in the higher modes of the flow. The kinetic energy of the first two modes covers up to 50% of the total kinetic energy - the first two modes in the case of the smooth cylinder have the lowest kinetic energy, whereas the first two modes in the case of the roughest cylinder have the highest kinetic energy. The similarity between the POD modes of the smooth and roughened cylinders might be due the fact that the actual Reynolds number range was below the transitional one.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20302 - Applied mechanics

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

European Journal of Mechanics B-Fluids

ISSN

0997-7546

e-ISSN

1873-7390

Svazek periodika

96

Číslo periodika v rámci svazku

November-December

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

11

Strana od-do

15-25

Kód UT WoS článku

000827411200002

EID výsledku v databázi Scopus

2-s2.0-85133278525