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Investigation of Synthetic Jet Flow Control Parameters for the Mitigation of Laminar Boundary Layer Separation.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Investigation of Synthetic Jet Flow Control Parameters for the Mitigation of Laminar Boundary Layer Separation./
Author:	Feero, Mark A.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
Description:	161 p.
Notes:	Source: Dissertation Abstracts International, Volume: 79-08(E), Section: B.
Contained By:	Dissertation Abstracts International79-08B(E).
Subject:	Aerospace engineering. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10690441
ISBN:	9780355813180

Investigation of Synthetic Jet Flow Control Parameters for the Mitigation of Laminar Boundary Layer Separation.
Feero, Mark A.

Investigation of Synthetic Jet Flow Control Parameters for the Mitigation of Laminar Boundary Layer Separation. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 161 p.

Source: Dissertation Abstracts International, Volume: 79-08(E), Section: B.

Thesis (Ph.D.)--University of Toronto (Canada), 2018.

An experimental study was performed to elucidate the effects of forcing parameters on the mitigation of boundary layer separation on an airfoil at low Reynolds number. Post- stall flow at a Reynolds number of 100,000 and angle-of-attack 12 degrees on a NACA 0025 airfoil served as the baseline for control with a synthetic jet actuator. This baseline flow is characterized by two dominant instabilities: the large scale vortex shedding in the wake of the airfoil, and the roll-up of vortices in the separated shear layer. The forcing parameters that were investigated were the blowing ratio, excitation frequency, and the chordwise forcing location.

ISBN: 9780355813180Subjects--Topical Terms:

686400
Aerospace engineering.

Investigation of Synthetic Jet Flow Control Parameters for the Mitigation of Laminar Boundary Layer Separation.
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100 1 $a Feero, Mark A. $3 1213806
245 1 0 $a Investigation of Synthetic Jet Flow Control Parameters for the Mitigation of Laminar Boundary Layer Separation.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2018
300 $a 161 p.
500 $a Source: Dissertation Abstracts International, Volume: 79-08(E), Section: B.
500 $a Advisers: Philippe Lavoie; Pierre E. Sullivan.
502 $a Thesis (Ph.D.)--University of Toronto (Canada), 2018.
520 $a An experimental study was performed to elucidate the effects of forcing parameters on the mitigation of boundary layer separation on an airfoil at low Reynolds number. Post- stall flow at a Reynolds number of 100,000 and angle-of-attack 12 degrees on a NACA 0025 airfoil served as the baseline for control with a synthetic jet actuator. This baseline flow is characterized by two dominant instabilities: the large scale vortex shedding in the wake of the airfoil, and the roll-up of vortices in the separated shear layer. The forcing parameters that were investigated were the blowing ratio, excitation frequency, and the chordwise forcing location.
520 $a The results concerning the effects on aerodynamic performance showed that for both drag reduction and lift increase, the benefits of control saturated with increasing blowing ratio. Initial improvements to lift and drag were due to the formation of a laminar separation bubble, followed by fully attached flow once a threshold blowing ratio was met. Positioning the slot at the most upstream location resulted in the lowest threshhold blowing ratio and produced the largest lift-to-drag ratios. A monotonic increase in threshold blowing ratio and decrease in lift-to-drag was observed as the slot location moved downstream. It was also found that while forcing at a frequency corresponding to the wake instability led to maximum lift increase, forcing in the range of the separated shear layer instability led to maximum drag reduction. High-frequency forcing, where the time scales of control are much smaller than those of the flow, was found to be least effective for improving performance.
520 $a The controlled flow dynamics revealed the presence of large vortices passing over the suction surface and highly unsteady flow when forcing at the wake instability frequency, whereas forcing in the range of the shear layer instability led to the production of a larger number of much smaller vortices. The latter case led to a thinner boundary layer in the time-averaged sense. Extraction of coherent and turbulent velocity fluctuations showed that the controlled flow was steady in time with high-frequency forcing.
590 $a School code: 0779.
650 4 $a Aerospace engineering. $3 686400
690 $a 0538
710 2 $a University of Toronto (Canada). $b Aerospace Science and Engineering. $3 845686
773 0 $t Dissertation Abstracts International $g 79-08B(E).
790 $a 0779
791 $a Ph.D.
792 $a 2018
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10690441