An almost subharmonic instability in the flow past rectangular cylinders
نویسندگان
چکیده
The three-dimensional instability of the flow past a 5 : 1 rectangular cylinder is investigated via Floquet analysis and direct numerical simulations. A quasi-subharmonic (QS) unstable mode detected, marking an important difference with bodies lower aspect ratio and/or smooth leading edge. QS becomes at Reynolds number (based on thickness free-stream velocity) $Re \approx 480$ ; its spanwise wavelength approximately three times thickness. structural sensitivity locates wavemaker region over longitudinal sides cylinder, indicating that triggered by mutual inviscid interaction vortices generated edge shear layer.
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ژورنال
عنوان ژورنال: Journal of Fluid Mechanics
سال: 2022
ISSN: ['0022-1120', '1469-7645']
DOI: https://doi.org/10.1017/jfm.2022.712