An investigation of fixed separation in quasi-periodic and aperiodic, unsteady, two-dimensional flows

This study asses the kinematic theory of fixed separation in unsteady, two-dimensional flows that has been proposed by Haller (2004). Experimental investigations were conducted that utilized the rotor-oscillator flow to drive low Reynolds number quasi-periodic and aperiodic flows. Flow separation was observed using flow visualization techniques that employed fluorescent dye. These experimental investigations show the existence of fixed separation in both quasi-periodic and aperiodic flows. The experimental results also suggest that the location of fixed separation is immune to relatively quick variations in the flow. Thus, the 'typical' behavior of a quasi-periodic or aperiodic flow dictates the location of fixed separation in addition to the amplitude of oscillation of the flow. Both of these findings imply that the time averaged zero skin friction point is a stronger predictor of separation, which supports the Haller (2004) criteria. Furthermore, while still premature, the experimental results have so far been corroborated by early numerical simulations of the Haller (2004) criteria in the quasi-periodic flows investigated in this study.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Helu, Moneer Mohammad

Advisor dc:contributor.advisor

• Thomas Peacock.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/40434

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40434