The source and evolution of turbulence in trailing vortex pairs

The reanalysis of data obtained from the experimental study of two different trailing vortex pairs has been conducted to obtain a more complete understanding of the turbulence structure of these flows. Statistical and spectral results, as well as filtered results and estimates of the effects of vortex wandering on the characteristics of the flows are presented. The results of the vortex pair are compared with the data from the experimental study of an isolated vortex conducted under similar testing conditions and model configuration to distinguish between the structure and effects of the the separate vortices from those of vortex interaction. The analysis of a counter-rotating vortex pair reveal that initially the vortices develop in a manner similar to an isolated vortex. The cores appear laminar and the turbulence structure outside them is dominated by the spiral wakes. After some distance, flow inside and outside the cores becomes much more turbulent. The cores begin to grow and decay. The results indicate that this change may be a result of wave instabilities developed in the cores. The analysis of the co-rotating vortex pair reveal that turbulence is present in the cores as they spiral about each other and move downstream. After a certain distance the cores merge into a single core, which contains more turbulence and is over twice the size of the pair that created it. As merger comes to completion, a symmetric core is formed which has much less turbulence. Merger appears to cause an increased rate of vortex decay.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Aerospace Engineering

Department dc:contributor.department

Aerospace Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1995

Author dc:creator

• Vogel, Christine M.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-01102009-063119

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/40549