Aeroelastic instability of differently porous U-profiles in crosswind direction

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F22%3A00557017" target="_blank" >RIV/68378297:_____/22:00557017 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.engmech.cz/im/proceedings/show_p/2022/153" target="_blank" >https://www.engmech.cz/im/proceedings/show_p/2022/153</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.21495/51-2-153" target="_blank" >10.21495/51-2-153</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Aeroelastic instability of differently porous U-profiles in crosswind direction

Popis výsledku v původním jazyce

Flow-induced vibrations of the flexibly mounted slender U-shaped beams allowed to oscillate in the crosswind direction only are studied experimentally in the wind tunnel. All beams are characterized by a cross section having a side ratio of along-wind to across-wind dimension equal to two. The effects of two depths of U profiles and two porosities of their flanges ( 0 % and 75 %) onto a loss of aeroelastic stability are investigated under the smooth flow conditions and for low Scruton numbers. The results indicate almost similar proneness of the non-porous beams to galloping-type oscillations to a rectangular prism with the same side ratio regardless their depth. The onset of across-wind galloping occurred in these cases at wind velocity very close to von-Kármán-vortex-resonance flow speed, even though the critical velocity predicted by the quasisteady theory is much lower. For porous and shallower U profile this asynchronous quenching also takesnplace. However, the higher flange porosity reduces significantly not only the vortex-shedding effect, but also causes an increase in the onset galloping velocity above the critical speed determined for non-porous profiles. In the case of deeper U-shaped beam, the effect of higher porosity even suppresses the proneness to galloping

Název v anglickém jazyce

Aeroelastic instability of differently porous U-profiles in crosswind direction

Popis výsledku anglicky

Flow-induced vibrations of the flexibly mounted slender U-shaped beams allowed to oscillate in the crosswind direction only are studied experimentally in the wind tunnel. All beams are characterized by a cross section having a side ratio of along-wind to across-wind dimension equal to two. The effects of two depths of U profiles and two porosities of their flanges ( 0 % and 75 %) onto a loss of aeroelastic stability are investigated under the smooth flow conditions and for low Scruton numbers. The results indicate almost similar proneness of the non-porous beams to galloping-type oscillations to a rectangular prism with the same side ratio regardless their depth. The onset of across-wind galloping occurred in these cases at wind velocity very close to von-Kármán-vortex-resonance flow speed, even though the critical velocity predicted by the quasisteady theory is much lower. For porous and shallower U profile this asynchronous quenching also takesnplace. However, the higher flange porosity reduces significantly not only the vortex-shedding effect, but also causes an increase in the onset galloping velocity above the critical speed determined for non-porous profiles. In the case of deeper U-shaped beam, the effect of higher porosity even suppresses the proneness to galloping

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20101 - Civil engineering

Projekt

<a href="/cs/project/GA19-21817S" target="_blank" >GA19-21817S: Neholonomní interakce a dynamická stabilita aeroelastických soustav</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název statě ve sborníku

Engineering mechanics 2022. Book of full texts

ISBN

978-80-86246-48-2

ISSN

1805-8248

e-ISSN

1805-8256

Počet stran výsledku

4

Strana od-do

153-156

Název nakladatele

Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences

Místo vydání

Prague

Místo konání akce

Milovy

Datum konání akce

9. 5. 2022

Typ akce podle státní příslušnosti

EUR - Evropská akce

Kód UT WoS článku

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