ISSN:
1432-1114
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The dynamic character of the hemisphere-cylinder wake was studied over the entire range of angles of attack, i.e. α=0° to 90°. The work was carried out in two wind tunnel facilities, using hot-wire anemometry. Velocity auto- and cross-spectra in the wake reveal that the leeward vortices exhibit periodic motions, with multiple dominant frequencies for 24°〈α〈42°, one single dominant frequency for 15°〈α〈22°, while no periodic activity is detected for α〈15°. In the regime 15°〈α〈42°, a new periodic heaving motion of the vortices is documented. Vortex heaving transitions to the more classical vortex shedding periodicity in the neighborhood of α=45°. Above α=55°, vortex shedding occurred at a single Strouhal number of 0.15. The limiting case α=90° was investigated in detail for semi-infinite and finite hemisphere-cylinder models and comparisons were made to axisymmetric bodies with different nose shapes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003480050305
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