Effects of Ns-DBD plasma actuators on turbulent shear layers

Ralf Lehmann, David Akins, Jesse C Little

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Citations (Scopus)

Abstract

The effects of nanosecond pulse driven dielectric barrier discharge (ns-DBD) plasma actuators on turbulent shear layers is examined experimentally on a mixing layer and backward facing step (BFS). The ns-DBD control mechanism is believed to be primarily thermal in contrast to most flow control actuators, including ac-DBDs, which rely on periodic or pulsed momentum to excite shear layer instabilities. Control authority using thermal perturbations has been demonstrated in various high speed shear flows yet many questions on fundamental physics and scaling remain unanswered. This work aims to provide insight into both ns-DBDs and thermal mechanisms in general for high amplitude aerodynamic flow control. Previous studies suggest the efficacy of ns-DBDs (and likely thermal perturbations in general) is strongly dependent on initial shear layer conditions, namely some measure of the initial thickness. In an effort to support this hypothesis, boundary layer suction is applied to a splitter plate upstream of a turbulent mixing layer origin. This successfully reduces the initial mixing layer momentum thickness, but does not result in substantial ns-DBD control authority. These results and the experimental conditions are documented in detail. Application of ns-DBD forcing to the turbulent shear layer downstream of a BFS having even smaller initial thickness produces the expected control authority at significantly lower pulse amplitude than employed in the mixing layer case. This supports the importance of initial shear layer thickness (rather than state) for estimating potential control authority by ns-DBD and thermal perturbations in general. In the context of past studies, this also suggests that the efficacy of thermal perturbations is likely dependent on the scale of energy deposition relative to the initial shear layer conditions. The dependence (or lack thereof) of this undefined amplitude parameter on Reynolds number based on some measure of initial shear layer thickness is currently unclear.

Original languageEnglish (US)
Title of host publicationAIAA AVIATION 2014 -7th AIAA Flow Control Conference
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
ISBN (Print)9781624102929
StatePublished - 2014
EventAIAA AVIATION 2014 -7th AIAA Flow Control Conference 2014 - Atlanta, GA, United States
Duration: Jun 16 2014Jun 20 2014

Other

OtherAIAA AVIATION 2014 -7th AIAA Flow Control Conference 2014
CountryUnited States
CityAtlanta, GA
Period6/16/146/20/14

Fingerprint

Actuators
Plasmas
Flow control
Momentum
Shear flow
Hot Temperature
Aerodynamics
Boundary layers
Reynolds number
Physics

ASJC Scopus subject areas

  • Aerospace Engineering
  • Mechanical Engineering

Cite this

Lehmann, R., Akins, D., & Little, J. C. (2014). Effects of Ns-DBD plasma actuators on turbulent shear layers. In AIAA AVIATION 2014 -7th AIAA Flow Control Conference American Institute of Aeronautics and Astronautics Inc..

Effects of Ns-DBD plasma actuators on turbulent shear layers. / Lehmann, Ralf; Akins, David; Little, Jesse C.

AIAA AVIATION 2014 -7th AIAA Flow Control Conference. American Institute of Aeronautics and Astronautics Inc., 2014.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Lehmann, R, Akins, D & Little, JC 2014, Effects of Ns-DBD plasma actuators on turbulent shear layers. in AIAA AVIATION 2014 -7th AIAA Flow Control Conference. American Institute of Aeronautics and Astronautics Inc., AIAA AVIATION 2014 -7th AIAA Flow Control Conference 2014, Atlanta, GA, United States, 6/16/14.
Lehmann R, Akins D, Little JC. Effects of Ns-DBD plasma actuators on turbulent shear layers. In AIAA AVIATION 2014 -7th AIAA Flow Control Conference. American Institute of Aeronautics and Astronautics Inc. 2014
Lehmann, Ralf ; Akins, David ; Little, Jesse C. / Effects of Ns-DBD plasma actuators on turbulent shear layers. AIAA AVIATION 2014 -7th AIAA Flow Control Conference. American Institute of Aeronautics and Astronautics Inc., 2014.
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