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The interaction between flow-induced vibration mechanisms of a square cylinder with varying angles of attack

Nemes, Andras and Zhao, Jisheng and Lo Jacono, David and Sheridan, John The interaction between flow-induced vibration mechanisms of a square cylinder with varying angles of attack. (2012) Journal of Fluid Mechanics, 710. 102-130. ISSN 0022-1120

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Official URL: http://dx.doi.org/10.1017/jfm.2012.353


This study examines the influence of angle of attack of a square section cylinder on the cylinder’s flow-induced vibration, where the direction of the vibration is transverse to the oncoming flow. Our experiments, which traversed the velocity–angle of attack parameter space in considerable breadth and depth, show that a low-mass ratio body can undergo combinations of both vortex-induced vibration and galloping. When the body has an angle of attack that makes it symmetric to the flow, such as when it assumes the square or diamond orientation, the two mechanisms remain independent. However, when symmetry is lost we find a mixed mode response with a new branch of vortex-induced oscillations that exceeds the amplitudes resulting from the two phenomena independently. The oscillations of this higher branch have amplitudes larger than the ‘upper branch’ of vortex-induced vibrations and at half the frequency. For velocities above this resonant region, the frequency splits into two diverging branches. Analysis of the amplitude response reveals that the transition between galloping and vortex-induced vibrations occurs over a narrow range of angle of incidence. Despite the rich set of states found in the parameter space the vortex shedding modes remain very similar to those found previously in vortex-induced vibration.

Item Type:Article
Additional Information:Thanks to Cambridge University Press. The definitive version is available at http://dx.doi.org/10.1017/jfm.2012.353
HAL Id:hal-00752464
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Other partners > Monash University (AUSTRALIA)
Laboratory name:
Deposited On:15 Nov 2012 17:11

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