Periodic Structures within the Formation Region of Trailing Vortices

David B. Sims-Williams; Steven Kaye; Simon Watkins

doi:10.4271/2006-01-1032

2006-04-03

Periodic Structures within the Formation Region of Trailing Vortices 2006-01-1032

Water tow-tank tests were performed for the Ahmed model at a range of “high-drag” backlight angles at Reynolds numbers of up to 1.3 × 10⁵. Dye was injected just upstream of the c-pillars and visualizations were recorded with a submerged CCD camera moving with the model.

Discrete sub-vortices were found to be shed periodically along the length of the c-pillar at Strouhal numbers (based on square root of frontal area) between 8 and 12. These sub-vortices were observed to undergo vortex pairing and then to roll up into the familiar c-pillar vortices. These observations are consistent with previously published observations for delta wings.

Wind tunnel tests were performed in order to provide Reynolds numbers of up to 1.6 × 10⁶. These revealed some spectral features which could be due to the shedding and pairing of discrete vortices from the c-pillar but the evidence was much less conclusive than at low Reynolds number.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Digital $37.00 Print $37.00

Preview Document

We also recommend:

Standards

SAE Mobilus®

Publications

News

Events

Professional Development

A World in Motion (PreK-12)

Participate with SAE

SAE Membership

Donate

Periodic Structures within the Formation Region of Trailing Vortices 2006-01-1032

SAE MOBILUS