Single Dielectric Barrier Discharge Plasma Actuators for Improved Airfoil Performance

Mabe, James H.; Calkins, Frederick T.; Wesley, Benjamin; Woszidlo, Rene; Taubert, Lutz; Wygnanski, I.

doi:10.2514/1.37638

Cited by 44 publications

(14 citation statements)

References 13 publications

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“…9 The limitations of low momentum AC-DBD plasma actuators are well-established. 32 This fact with the results of Figure 6 show that the EHD effects of NS-DBD are likely not a mechanism for flow control in the Re discussed in this work. Rather, rapid localized heating that excites natural flow instabilities is believed to be the source of control authority similar to that observed for LAFPAs in both experiments and computations.…”

Section: B Behavior In Quiescent Airsupporting

confidence: 62%

Separation Control with Nanosecond-Pulse-Driven Dielectric Barrier Discharge Plasma Actuators

et al. 2012

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Section: B Behavior In Quiescent Airsupporting

confidence: 62%

Separation Control with Nanosecond-Pulse-Driven Dielectric Barrier Discharge Plasma Actuators

et al. 2012

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“…The objectives for separation control have covered various types of fluid and transport machinery. For the twodimensional airfoil flows, NACA airfoils [5][6][7][8][9][10], a flat-plate airfoil [11,12], and a low-Reynolds-number airfoil [13,14] have been investigated. Moreover, a linear cascade of turbine blades [15][16][17], a vertical-axis wind turbine [18], and cylinder and bluff-body flows [19][20][21][22] have also been the target of flow separation control.…”

mentioning

confidence: 99%

Multifactorial Effects of Operating Conditions of Dielectric-Barrier-Discharge Plasma Actuator on Laminar-Separated-Flow Control

et al. 2015

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A substantial number of large-eddy simulations are conducted on separated flow controlled by a dielectric barrier discharge plasma actuator at a Reynolds number of 63,000. In the present paper, the separated flow over a NACA 0015 airfoil at an angle of attack of 12 deg, which is just poststall, is used as the base flow for separation control. The effects of the location and operating conditions of the plasma actuator on the separation control are investigated by a parametric study. The control effect is evaluated based on the improvement of not only the lift coefficient but also the drag coefficient over an airfoil. The most effective location of the plasma actuator for both lift and drag improvement is precisely confirmed to be upstream of the natural separation point. Even a low burst ratio is found to be sufficient to obtain the same improvements as the cases with a high burst ratio. The effective nondimensional burst frequency F is observed at 4 ≤ F ≤ 6 for the improvement in the lift coefficient and at 6 ≤ F ≤ 20 for that in the drag coefficient.The lift/drag ratio shows a clear peak at 6 ≤ F ≤ 10. To clarify the mechanism of the laminar-separation control, the effect of a turbulent transition is investigated. There is a clear relationship between the separation control effect and the turbulent transition at the shear layer. An earlier and smoother transition case shows greater improvements in the lift and drag coefficients. Flow analyses show that the cases with early and smooth turbulent transition can attach the separated flow further upstream, resulting in a higher suction peak of the pressure coefficient. In addition, another mechanism of the separation control is observed in which the lift coefficient is improved, not by the reattachment through the turbulent transition but by the large-scale vortex shedding induced by the actuation. It is possible to separate these two dominant mechanisms based on the effect of the turbulent transition on the separation control. Nomenclature a = speed of sound BR = burst ratio C D = drag coefficientlength scale D c = ratio between electrostatic body force added by plasma actuator and dynamic pressure D c;effe = effective D c value E i = electric field vector induced by plasma actuator e = total energy per unit volume F base = nondimensional base frequency for sine wave of input voltage; f base c∕u ∞ F = nondimensional frequency of burst wave; f c∕u ∞ f = frequency f base = base frequency for sine wave of input voltage f = frequency of burst wave M ∞ = freestream Mach number Pr = Prandtl number p = pressure Q c = electric charge q i = heat flux vector Re = Reynolds number St = Strouhal number S Suzen = body force vector determined from Suzen model S i = body force vector; Q c E i T = burst wave period T base = period of sine wave T off = period when sine wave switch is off during burst wave period T on = period when sine wave switch is on during burst wave period t = time u = velocity in chord direction . Member AIAA. Article in Advance / 1 AIAA JOURNAL Downloaded by U...

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“…Sosa et al (2007) placed a DBD plasma actuator over the suction side of an airfoil near the leading edge, where they found that the large-scale separation region was reduced or even eliminated, resulting in a large increment in lift. Mabe et al (2009) used a DBD plasma actuator for flow separation control of a NACA 0021 airfoil. Due to the limited applicability of the device, the effectiveness of control was restricted to relatively low Reynolds number of 100 000, such as those associated with MAVs.…”

Section: Plasma Flow Controlmentioning

confidence: 99%

Flow control over an airfoil using virtual Gurney flaps

2015

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Flow control over a NACA 0012 airfoil is carried out using a dielectric barrier discharge (DBD) plasma actuator at the Reynolds number of 20 000. Here, the plasma actuator is placed over the pressure (lower) side of the airfoil near the trailing edge, which produces a wall jet against the free stream. This reverse flow creates a quasi-steady recirculation region, reducing the velocity over the pressure side of the airfoil. On the other hand, the air over the suction (upper) side of the airfoil is drawn by the recirculation, increasing its velocity. Measured phase-averaged vorticity and velocity fields also indicate that the recirculation region created by the plasma actuator over the pressure surface modifies the near-wake dynamics. These flow modifications around the airfoil lead to an increase in the lift coefficient, which is similar to the effect of a mechanical Gurney flap. This configuration of DBD plasma actuators, which is investigated for the first time in this study, is therefore called a virtual Gurney flap. The purpose of this investigation is to understand the mechanism of lift enhancement by virtual Gurney flaps by carefully studying the global flow behaviour over the airfoil. First, the recirculation region draws the air from the suction surface around the trailing edge. The upper shear layer then interacts with the opposite-signed shear layer from the pressure surface, creating a stronger vortex shedding from the airfoil. Secondly, the recirculation region created by a DBD plasma actuator over the pressure surface displaces the positive shear layer away from the airfoil, thereby shifting the near-wake region downwards. The virtual Gurney flap also changes the dynamics of laminar separation bubbles and associated vortical structures by accelerating laminar-to-turbulent transition through the Kelvin-Helmholtz instability mechanism. In particular, the separation point and the start of transition are advanced. The reattachment point also moves upstream with plasma control, although it is slightly delayed at a large angle of attack.

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Single Dielectric Barrier Discharge Plasma Actuators for Improved Airfoil Performance

Cited by 44 publications

References 13 publications

Separation Control with Nanosecond-Pulse-Driven Dielectric Barrier Discharge Plasma Actuators

Separation Control with Nanosecond-Pulse-Driven Dielectric Barrier Discharge Plasma Actuators

Multifactorial Effects of Operating Conditions of Dielectric-Barrier-Discharge Plasma Actuator on Laminar-Separated-Flow Control

Flow control over an airfoil using virtual Gurney flaps

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