Journal of Fluid Mechanics

Characteristics of vorticity fluctuations in a turbulent wake

R. A.  Antonia a1, L. W. B.  Browne a1 and D. A.  Shah a1
a1 Department of Mechanical Engineering, University of Newcastle, NSW 2308, Australia

Article author query
antonia ra   [Google Scholar] 
browne lw   [Google Scholar] 
shah da   [Google Scholar] 


Measurements of the lateral components of the vorticity fluctuation have been made in the self-preserving turbulent wake of a circular cylinder. Each component was obtained separately using two X-wires separated in the appropriate lateral directions. The two velocity derivatives which make up the streamwise vorticity component were also determined but not simultaneously. An approximation to the streamwise vorticity was made from these measurements. Moments, probability density functions and spectra of the three vorticity components across the wake are presented and discussed. The high-wavenumber behaviour of the spectra is compared with calculations, based on local isotropy. Satisfactory agreement with the calculations is obtained for the lateral vorticity components over a significant high-wavenumber range. The approximated streamwise vorticity spectrum tends towards the isotropic calculation at very large wavenumbers.

(Published Online April 21 2006)
(Received January 21 1987)
(Revised September 9 1987)