Vorticity characteristics of the turbulent intermediate wake

✍ Scribed by J. Mi; R. A. Antonia

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 829 KB
• Volume: 20
• Category: Article
• ISSN: 0723-4864
• DOI: 10.1007/bf00191020

✦ Synopsis

Measurements of the lateral components coj (j = 2 and 3) of the vorticity fluctuation vector have been made, using a vorticity probe consisting of two X-wires, in the intermediate wake of a circular cylinder. The effect of the spatial resolution of the probe on the measurement of coj has been studied. As the spatial resolution impairs, the variance and flatness factor of coj decrease whereas the skewness of coj increases. Reasonably accurate values of eg~ can be obtained by applying spectral corrections for the spatial resolution effect.

Near the beginning of the intermediate wake, the variance of co 2 is larger than that of co3 due to the significant contribution from ribs which connect consecutive spanwise roll vortices. This difference decreases with downstream distance. Also, the presence of the rolls is reflected by a local extremum in the skewness of co 3 on each side of the wake centerline. The magnitude of the extremum decreases with downstream distance.