Mean lift generation on cylinders induced with plasma actuators

Sosa, Roberto; Artana, Guillermo; Bénard, Nicolas; Moreau, E.

doi:10.1007/s00348-011-1108-0

Cited by 17 publications

(17 citation statements)

References 34 publications

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“…Many previous studies have discussed the optimum burst frequency for separated flow control in airfoils [7,32], turbine blades [15], flat plates [11,12], and cylinders [19,33] at Reynolds numbers of 10 4 -10 5 . In these investigations of the optimum burst frequency, the lift improvement was mostly used to evaluate the effect of separation control.…”

Section: Effect Of the Burst Frequencymentioning

confidence: 99%

“…The key parameters of the burst mode are the burst ratio (BR T on ∕T) and the burst frequency (f 1∕T). Since separation control is significantly influenced by the settings of the burst wave, there have been a number of discussions about the optimum values of these parameters [7,11,12,15,24,32,33]. Moreover, the influences of these configurations and operating conditions are complexly intertwined with each other.…”

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confidence: 99%

“…Meanwhile, for the burst mode, since the effect of the direct momentum is very small compared with that of the normal mode, other driven mechanisms may exist in the burst mode. Many studies have suggested that the burst actuation with the frequency of the natural vortex shedding of the separated flow leads to a significant improvement in aerodynamic performance [7,11,12,15,24,32,33] because the burst actuation with that frequency effectively promotes two-dimensional vortex shedding. Through vortex shedding, the momentum can be induced from the freestream to the boundary layer in addition to the effect of vortex convection.…”

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confidence: 99%

“…Through vortex shedding, the momentum can be induced from the freestream to the boundary layer in addition to the effect of vortex convection. In these studies [7,11,12,15,24,32,33], the optimum burst frequency was suggested to be 0.2-2.0, which was nondimensionalized by the freestream velocity and characteristic length scale (F f c ref ∕u ∞ ). On the other hand, Asada and Fujii [35] have shown that a nondimensional burst frequency F 6 is more effective than F 1.…”

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confidence: 99%

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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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Section: Effect Of the Burst Frequencymentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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

et al. 2015

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“…This induces a wall jet on the edge of the exposed electrode. As a flow control method, the plasma actuators have been studied on various aerodynamic research objects in wind tunnel, such as airfoil, [14][15][16] wing, [17][18][19][20] cylinder, [21][22][23][24] turbines blade, 25 and compressor cascade.…”

Section: Introductionmentioning

confidence: 99%

Coherent structures induced by dielectric barrier discharge plasma actuator

Zhang

Choi

et al. 2017

Mod. Phys. Lett. B

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The structures of a flow field induced by a plasma actuator were investigated experimentally in quiescent air using high-speed Particle Image Velocimetry (PIV) technology. The motivation behind was to figure out the flow control mechanism of the plasma technique. A symmetrical Dielectric Barrier Discharge (DBD) plasma actuator was mounted on the suction side of the SC (2)-0714 supercritical airfoil. The results demonstrated that the plasma jet had some coherent structures in the separated shear layer and these structures were linked to a dominant frequency of f 0 = 39 Hz when the peak-to-peak voltage of plasma actuator was 9.8 kV. The high speed PIV measurement of the induced airflow suggested that the plasma actuator could excite the flow instabilities which lead to production of the roll-up vortex. Analysis of transient results indicated that the roll-up vortices had the process of formation, movement, merging and breakdown. This could promote the entrainment effect of plasma actuator between the outside airflow and boundary layer flow, which is very important for flow control applications.

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Flow separation control over airfoils using DBD plasma body force

Khoshkhoo

Jahangirian

2014

J Braz. Soc. Mech. Sci. Eng.

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usually the flow behavior is laminar, which is important for control of the flow [2].Methods to flow separation control include active and passive techniques which are based on energy expenditure and controlled by command. Passive separation control techniques generally constitute geometric changes such as vortex generator, slotted flaps/slats, etc. These control elements are effective if the aircraft is operating in a flight regime that is in their design envelope. However, in off-design conditions, passive control elements can have detrimental effects that are often manifested in the form of increased drag [3]. Active separation control techniques have benefits of passive techniques without their disadvantage in off-design conditions. Also, these techniques have the potential to be implemented in a feedback system that can create more benefits in flight efficiency and maneuverability [3].Dielectric barrier discharge (DBD) plasma actuator is one of the active flow control devices that have been successfully used in aerodynamic flow control applications. Thus, considerable researches have been carried out on DBD plasma actuators over the past decade [4]. The examples of aerodynamic flow control applications by DBD plasma actuators include separation control in leading edge [5, 6], trailing edge [3, 7], bluff bodies [8], low pressure turbine blade [9, 10], axial compressor [11], flow control over a hump [12], Stabilizing a laminar boundary layer [13, 14], bluff body induced sound control [15], airfoil lift increasing [16], etc. Special characteristics of DBD plasma actuator over traditional flow control devices include reduction in size, weight and drag, increasing reliability, inexpensiveness, wide frequency bandwidth, rapid on-off capability, no moving parts, low energy consumption, and increasing stealth.The actuator consists of two asymmetrical metal electrodes separated by a dielectric layer, normally kapton, or Abstract The body force effects of plasma origin on the flow over a NACA 0015 airfoil are investigated by numerical simulation. The plasma actuator effect is estimated based on a phenomenological DBD plasma model coupled with 2-dimentional compressible Navier-Stokes equations. The equations are solved using an explicit finite volume method on unstructured grids. The responses of a separated flow field to the effects of a plasma actuator body force in various magnitudes and locations are presented. Also the effects of plasma region dimensions on the flow separation control are studied. It is found that the dimensions of plasma region, the magnitude of the body force, and the location of the plasma actuator all have significant impacts on the separation control.

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Mean lift generation on cylinders induced with plasma actuators

Cited by 17 publications

References 34 publications

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

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

Coherent structures induced by dielectric barrier discharge plasma actuator

Flow separation control over airfoils using DBD plasma body force

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