Enabling micro synthetic jet actuators in boundary layer separation control using flow instability

Hong, G

Enabling micro synthetic jet actuators in boundary layer separation control using flow instability

Hong, G

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Publication Type:: Conference Proceeding
Citation:: Proceedings of the 16th Australasian Fluid Mechanics Conference, 16AFMC, 2007, pp. 887 - 891
Issue Date:: 2007-12-01

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Field	Value	Language
dc.contributor.author	Hong, G https://orcid.org/0000-0002-1905-1161	en_US
dc.date.issued	2007-12-01	en_US
dc.identifier.citation	Proceedings of the 16th Australasian Fluid Mechanics Conference, 16AFMC, 2007, pp. 887 - 891	en_US
dc.identifier.isbn	9781864998948	en_US
dc.identifier.uri	http://hdl.handle.net/10453/7236
dc.description.abstract	Research on synthetic jet actuators (SJAs) has shown great potential of using SJAs in control of boundary layer flow separation to reduce the drag and increase the efficiency of aerodynamic devices. The challenge lies in developing an actuator not only small, light, robust and economic, but also capable of reaching the control objectives. This paper presents an idea of using the flow instability to enhance the actuation of a SJA. In the case of controlling laminar separation, the SJA is used to trigger frictional Tollmien-Schlichting (T-S) instability. At a forcing frequency strategically determined, the triggered T-S instability which is originally weak can be enhanced by the frictionless Kelvin- Helmholtz (K-H) instability of the baseline flow, until the T-S instability becomes substantially strong to resist the separation. The effective actuation of a SJA in resisting laminar separation caused by adverse pressure gradient in a boundary layer is demonstrated by experimental results of profiles of mean and fluctuating velocities. The orifice diameter, which is the characteristic dimension, of the SJA is 500 μm. The forcing voltage is only ±7.5V., and the forcing frequency is 100 Hz. The Reynolds number is in a range of 1.78×10 5∼2.24×10 5. Boundary layer properties are used to understand the associated physics, and disturbance intensity is first time used to evaluate the effectiveness of the SJA. Analysis of the experimental results led to the conclusion that flow instability plays a critical role in enabling a micro SJA and also in making the control effectiveness less dependent or independent of the detailed structure and size of the actuator.	en_US
dc.relation.ispartof	Proceedings of the 16th Australasian Fluid Mechanics Conference, 16AFMC	en_US
dc.title	Enabling micro synthetic jet actuators in boundary layer separation control using flow instability	en_US
dc.type	Conference Proceeding
utslib.for	0913 Mechanical Engineering	en_US
utslib.for	091305 Energy Generation, Conversion and Storage Engineering	en_US
dc.location.activity	Crown Plaza, Gold Coast, Australia	en_US
dc.location.activity	Perth, Australia
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology/School of Mechanical and Mechatronic Engineering
utslib.copyright.status	open_access
pubs.publication-status	Published	en_US

Abstract:

Research on synthetic jet actuators (SJAs) has shown great potential of using SJAs in control of boundary layer flow separation to reduce the drag and increase the efficiency of aerodynamic devices. The challenge lies in developing an actuator not only small, light, robust and economic, but also capable of reaching the control objectives. This paper presents an idea of using the flow instability to enhance the actuation of a SJA. In the case of controlling laminar separation, the SJA is used to trigger frictional Tollmien-Schlichting (T-S) instability. At a forcing frequency strategically determined, the triggered T-S instability which is originally weak can be enhanced by the frictionless Kelvin- Helmholtz (K-H) instability of the baseline flow, until the T-S instability becomes substantially strong to resist the separation. The effective actuation of a SJA in resisting laminar separation caused by adverse pressure gradient in a boundary layer is demonstrated by experimental results of profiles of mean and fluctuating velocities. The orifice diameter, which is the characteristic dimension, of the SJA is 500 μm. The forcing voltage is only ±7.5V., and the forcing frequency is 100 Hz. The Reynolds number is in a range of 1.78×10 5∼2.24×10 5. Boundary layer properties are used to understand the associated physics, and disturbance intensity is first time used to evaluate the effectiveness of the SJA. Analysis of the experimental results led to the conclusion that flow instability plays a critical role in enabling a micro SJA and also in making the control effectiveness less dependent or independent of the detailed structure and size of the actuator.

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http://hdl.handle.net/10453/7236