The ADVINT Program

Smith, David M.; Dickey, Eric D.; VonKlein, Terry

doi:10.2514/6.2006-2854

Cited by 17 publications

(6 citation statements)

References 3 publications

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“…Synthetic-jet actuation at St act = O(1) has also been applied to flaps with emphasis on high-lift systems. Smith et al [36] used voicecoil actuators to achieve significant lift increments on a super short takeoff and landing (SSTOL) model (0.2 for takeoff and 0.5 for landing at flap deflections of 40…”

Section: Synthetic-jet Flow Controlmentioning

confidence: 99%

Some aspects of aerodynamic flow control using synthetic-jet actuation

Glezer

2011

Phil. Trans. R. Soc. A.

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Aerodynamic flow control effected by interactions of surface-mounted synthetic (zero net mass flux) jet actuators with a local cross flow is reviewed. These jets are formed by the advection and interactions of trains of discrete vortical structures that are formed entirely from the fluid of the embedding flow system, and thus transfer momentum to the cross flow without net mass injection across the flow boundary. Traditional approaches to active flow control have focused, to a large extent, on control of separation on stalled aerofoils by means of quasi-steady actuation within two distinct regimes that are characterized by the actuation time scales. When the characteristic actuation period is commensurate with the time scale of the inherent instabilities of the base flow, the jets can effect significant quasi-steady global modifications on spatial scales that are one to two orders of magnitude larger than the scale of the jets. However, when the actuation frequency is sufficiently high to be decoupled from global instabilities of the base flow, changes in the aerodynamic forces are attained by leveraging the generation and regulation of 'trapped' vorticity concentrations near the surface to alter its aerodynamic shape. Some examples of the utility of this approach for aerodynamic flow control of separated flows on bluff bodies and fully attached flows on lifting surfaces are also discussed.

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Section: Synthetic-jet Flow Controlmentioning

confidence: 99%

Some aspects of aerodynamic flow control using synthetic-jet actuation

Glezer

2011

Phil. Trans. R. Soc. A.

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“…Several investigations have implemented "lowfrequency" AFC [i.e., St act ~ O(1)] with synthetic jets, including Smith, et al 9 who used voice-coil type synthetic jets on a powered model of a SSTOL airplane to achieve lift increments of ΔC L = 0.2 for takeoff (flap deflection δ = 40º) and 0.5 for landing (δ = 50º). In 2-D testing, these authors demonstrated a 20-40% increase in C L , depending on angle of attack, at Re c = 7.5•10 5 and a blowing ratio of 3.6 on a similar system using a slat and a flap at δ = 40º.…”

Section: Introductionmentioning

confidence: 99%

High-Lift Enhancement Using Active Flow Control

DeSalvo

Whalen

Glezer

2012

6th AIAA Flow Control Conference

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The high-lift performance of an airfoil with a single-element flap is enhanced using fluidic actuation based on synthetic jet technology. Acutation is implemented using a spanwise array of individually controlled discrete synthetic jets with variable spanwise spacing that issue in a direction nominally-tangential to the flap immediately upstream of separation. The jets are used to engender and manipulate concentrations of vorticity in a manner that leads to improved flow attachment. The resulting increase in suction upstream and downstream of the jet array leads to a substantial increase in lift (at  = 25º, Re c = 3.3•10 5 and α = 4º, C L of up to 0.82 relative to the unactuated flow can be realized). The effect of the spanwise actuation wavelength  is investigated with the objective of optimizing the actuation momentum coefficient C  . It is shown that for a given C L , C  has a minimum for some spanwise actuation wavelength. Measurements of the three-dimensional flow field in the vicinity of an actuator jet show that flow attachment is accompanied by the formation of a counterrotating streamwise vortex pair, and favorable streamwise pressure gradient downstream of the actuator.

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“…The benefits of such a simplification have fueled two major research projects in this area. The ADVINT program on the Boeing tilt-wing supershort takeoff and landing transport [2][3][4][5][6][7] and a parallel work by NASA [8][9][10][11][12][13] have produced significant developments using AFC via both nonzero and zero-net-mass flux (ZNMF) periodic excitation [14], which is well established in the flow control community [15]. Some of the pertinent findings of these programs with respect to lift enhancement are relevant to this paper and warrant mention here.…”

Section: Introductionmentioning

confidence: 99%

High-Lift Airfoil Separation with Dielectric Barrier Discharge Plasma Actuation

Little

Samimy

2010

AIAA Journal

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The efficacy of a single dielectric barrier discharge plasma actuator for controlling turbulent boundary-layer separation from the deflected flap of a high-lift airfoil is investigated between Reynolds numbers of 240,000 (15 m=s) and 750,000 (45 m=s). Momentum coefficients for the dielectric barrier discharge plasma actuator are approximately an order of magnitude lower than those usually employed for such studies, yet control authority is still realized through amplification of natural vortex shedding from the flap shoulder, which promotes momentum transfer between the freestream and separated region. This increases dynamic loading on the flap and further organizes turbulent fluctuations in the wake. The measured lift enhancement is primarily due to upstream effects from increased circulation around the entire model, rather than full reattachment to the deflected flap surface. Lift enhancement via instability amplification is found to be relatively insensitive to changes in angle of attack, provided that the separation location and underlying dynamics do not change. The modulation waveform used to excite lowfrequency perturbations with a high-frequency plasma-carrier signal has a considerable effect on the actuator performance. Control authority decreases with increasing Reynolds number and flap deflection, highlighting the necessity for further improvement of plasma actuators for use in realistic takeoff and landing transport aircraft applications. These findings are compared to studies on a similar high-lift platform using piezoelectric-driven zeronet-mass flux actuation. Nomenclature

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The ADVINT Program

Cited by 17 publications

References 3 publications

Some aspects of aerodynamic flow control using synthetic-jet actuation

Some aspects of aerodynamic flow control using synthetic-jet actuation

High-Lift Enhancement Using Active Flow Control

High-Lift Airfoil Separation with Dielectric Barrier Discharge Plasma Actuation

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