Phase front analysis of laminar vortex streets

The continuous formation and development of a laminar vortex street behind a circular cylinder has been modelled as a Huygens-type wave process. The phase of a point next to the cylinder is defined by the amplitude and phase of secondary wavelet centres along the preceding vortexin the near wake. Vortices are located at places where the phase in each cycle is 0 or n. The phase is defined from a Kirchhoff-type phase-amplitude integral which is derived from the Biot-Savart law. Model predictions agree with reported experimental results on cylinders with steps and tapers, and with our own tapered cylinder experiments. To test the predictive power of the model, with regards to preset phase, experiments were performed with new experimental techniques that allow us to set the start-up phase of vortex shedding. The experiments yield known starting conditions, which, when introduced into the phase front model, yield predictions of the street in good agreement with the experiments with regard to the shape and position of the shed vortices in the wake.

Name thesis:degree_name

Doctor of Philosophy - PhD

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Physics

Grantor dc:publisher

University of British Columbia

Year dc:date

1992

Author dc:creator

• Lefrançois, Marcel

Statement dc:rights

• For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

Language dc:language

eng

Handle dc:identifier

http://hdl.handle.net/2429/1930

OAI identifier oai:identifier

oai:circle.library.ubc.ca:2429/1930