Overview of Active Flow Control Actuator Development at NASA Langley Research Center

Schaeffler, Norman W.; Hepner, Timothy E.; Jones, Gregory S.; Kegerise, Michael A.

doi:10.2514/6.2002-3159

Cited by 36 publications

(20 citation statements)

References 8 publications

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“…8 and shows the development of two vortices at the vicinity of the slot and the existence of a lowest saddle point that defines the near-wake and the far-wake flow region. The same flow topology has already been shown by Smith et al Smith and Glezer (2002) and Schaffler et al Schaffler et al (2002). In the synthetic jet flow, we can identify a near-field and a farfield regions delimited by the red line in Fig.…”

Section: Spatial Behavior Of the Induced Flowsupporting

confidence: 60%

“…Alternating suction-blowing mechanism or synthetic jet are efficient methods for control because they improve the aerodynamic performances. Several synthetic jet actuators are designed, they can be grouped into three categories: the piezoelectric devices (Smith and Glezer (2002), Schaffler et al (2002)), mechanical devices (Rediniotis et al (1999), Crittenden and Glezer (2006) , Joseph et al (2013)) and the acoustic devices (Erk (1997) , McCormick (2000 , Tesar and Kordik (2010) ). A constraint of the piezoelectric actuators is that the output velocity depends on the resonance frequency contrary to the mechanical actuators where the expulsion speed increases linearly with the frequency.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental Study of Flow Control on Bluff Body using Piezoelectric Actuators

Tounsi¹,

Mestiri²,

Keirsbulck³

et al. 2016

JAFM

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Active flow control is experimentally investigated on a car-type bluff body. The actuation is based on a synthetic jet actuator placed at the top of the Ahmed body rear window. In the present paper, a synthetic jet characterization is presented, the frequencies and the optimal amplitudes with regard to the spatial evolution are analyzed. All the measurements are carried out in a wind tunnel at Reynolds numbers based on the body length between 10 6 and 3 × 10 6 . The bluff body shows a maximum drag reduction of 10% when optimal control is applied. Independent effect of the reduced frequency and the momentum coefficient actuation parameters on the drag reduction are also detailed in the present paper. This reduction induces changes in the flow field due to the piezoelectric actuation. The flow topology modification is investigated via particle image velocimetry measurements in order to estimate the flow response to a local excitation and to understand the mechanism involved in the aerodynamic drag control.

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Section: Spatial Behavior Of the Induced Flowsupporting

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Experimental Study of Flow Control on Bluff Body using Piezoelectric Actuators

Tounsi¹,

Mestiri²,

Keirsbulck³

et al. 2016

JAFM

View full text Add to dashboard Cite

show abstract

“…Nonlinear bimorphs may also be useful on smaller scales, including micro-fluidic controls and nanoscale electrical switches. 44,45 …”

Section: Discussionmentioning

confidence: 99%

Thermally Driven Morphing and Snap-Through Behavior of Hybrid Laminate Shells

2016

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“…12 For cavity flow control, the requirement for low-frequency forcing devices is a bandwidth that includes the Rossiter frequencies of interest. 27 Candidate lowfrequency actuators include piezoelectric flaps with deflections on the order of the viscous sublayer of the boundary layer approaching the cavity, 1,20 steady and pulsating blowing jets, 29 successfully demonstrated cavity tone suppression across a broad range of frequencies without exciting additional tones at supersonic speeds by using a powered resonance tube, a high-frequency fluidic device whose frequency is an order of magnitude greater than the Rossiter modes (see Refs. [30][31][32].…”

Section: Introductionmentioning

confidence: 99%

Logic-Based Active Control of Subsonic Cavity Flow Resonance

Debiasi

Samimy

2004

AIAA Journal

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We present the results of an experimental investigation for controlling a shallow cavity flow in the Mach number range 0.25-0.5. The flow exhibits the characteristic staging behavior predicted by the semi-empirical Rossiter formula with multiple modes in the Mach number range 0.32-0.38 and a single strong mode in other Mach numbers. A survey of the velocity at the exit of the zero net mass flow compression-driver actuator used for control reveals that its amplitude is frequency dependent and its behavior is little influenced by the main flow. Forcing the Mach 0.3 flow indicated that the actuator has good authority over a large range of frequencies, with reduction of spectral peaks observed at some forcing frequencies. We took advantage of this phenomenon to develop a logicbased controller that searches the frequency space and maintains the optimal forcing frequency for peak reduction at each Mach number. Optimal frequencies and the corresponding reduced resonance have been obtained for all of the flow conditions explored. The physics of optimal frequency forcing as well as some characteristics of the logic-based controller are discussed.

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Overview of Active Flow Control Actuator Development at NASA Langley Research Center

Cited by 36 publications

References 8 publications

Experimental Study of Flow Control on Bluff Body using Piezoelectric Actuators

Experimental Study of Flow Control on Bluff Body using Piezoelectric Actuators

Thermally Driven Morphing and Snap-Through Behavior of Hybrid Laminate Shells

Logic-Based Active Control of Subsonic Cavity Flow Resonance

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