Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-04-30T12:16:19.299Z Has data issue: false hasContentIssue false

Wakes and vortex streets generated by translating force and force doublet: laboratory experiments

Published online by Cambridge University Press:  06 April 2006

Y. D. AFANASYEV
Affiliation:
Memorial University of Newfoundland, Department of Physics and Physical Oceanography, St John's, NL, Canada, A1B 3X7 yakov@physics.mun.ca
V. N. KORABEL
Affiliation:
Memorial University of Newfoundland, Department of Physics and Physical Oceanography, St John's, NL, Canada, A1B 3X7 yakov@physics.mun.ca

Abstract

Wakes and vortex streets such as those occurring behind towed or self-propelled bodies are generated by moving localized forces in a viscous fluid at moderate values of the Reynolds number, $\hbox{\it Re}\,{\sim}\,10^{2}$. The forcing is provided by an electromagnetic method and allows us to create a ‘virtual’ body without introducing any solid objects into the fluid. Characteristics of stable and unstable wakes, in particular the shedding frequency, are measured in the space of control parameters, namely the magnitude of the forcing and the speed of translational motion of the forcing. The results for a single force presented in the dimensionless form of the Strouhal number demonstrate quantitative similarity to those for the classical flow around a cylinder. The problem considered here has an extra degree of freedom compared to the problem of the flow around a cylinder and exhibit a wider array of different regimes. These regimes are documented in both our visualization experiments and particle image velocimetry measurements.

Type
Papers
Copyright
© 2006 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)