Attenuation of Tollmien–Schlichting Waves Using Plasma Actuator Vortex Generators

Barckmann, K.; Tropea, Cameron; Grundmann, Sven

doi:10.2514/1.j053043

Cited by 23 publications

(3 citation statements)

References 16 publications

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“…Inside the boundary layer a crossflow (CF) velocity component perpendicular to the local potential-flow direction arises. The CF velocity profile is inflectional, Control of crossflow-vortex-induced transition by unsteady control vortices 429 of boundary-layer streaks, see Hanson et al (2014), Riherd & Roy (2014), or (iv) the spanwise modulation of the flow field, see Barckmann, Tropea & Grundmann (2015), .…”

Section: Introductionmentioning

confidence: 99%

Control of crossflow-vortex-induced transition by unsteady control vortices

Guo

Kloker

2019

J. Fluid Mech.

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The fundamental mechanisms of a hitherto unstudied approach to control the crossflow-induced transition in a three-dimensional boundary layer employing unsteady control vortices are investigated by means of direct numerical simulations. Using a spanwise row of blowing/suction or volume-force actuators, subcritical travelling crossflow vortex modes are excited to impose a stabilizing (upstream) flow deformation (UFD). Volume forcing mimics the effects of alternating current plasma actuators driven by a low-frequency sinusoidal signal. In this case the axes of the actuators are aligned with the wave crests of the desired travelling mode to maximize receptivity and abate the influence of other unwanted, misaligned modes. The resulting travelling crossflow vortices generate a beneficial mean-flow distortion reducing the amplification rate of naturally occurring steady or unsteady crossflow modes without invoking significant secondary instabilities. It is found that the stabilizing effect achieved by travelling control modes is somewhat weaker than that achieved by the steady modes in the classical UFD method. However, the energy requirements for unsteady-UFD plasma actuators would be significantly lower than for steady UFD because the approach makes full use of the inherent unsteadiness of the plasma-induced volume force with alternating-current-driven actuators. Also, the input control amplitude can be lower since unsteady crossflow vortex modes grow stronger in the flow.

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Section: Introductionmentioning

confidence: 99%

Control of crossflow-vortex-induced transition by unsteady control vortices

Guo

Kloker

2019

J. Fluid Mech.

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“…In this research the electrodes of the plasma actuator were elongated in the spanwise direction of the boundary layer flow such that the forcing was applied in the direction parallel to the flow (streamwise direction). However, Barckmann et al [67] later used a spanwise array of plasma actuators to generated streamwise oriented streaks to stabilize the TS wave; the idea was demonstrated earlier by Fransson et al [68] to be an effective control method, albeit using mechanical vortex generators.…”

Section: Applications Of Dbd Plasma Actuators In Flow Controlmentioning

confidence: 99%

Laminar Boundary-Layer Response to Step Input by an Array of Plasma Actuators

2022

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Bypass transition is a subcritical transition pathway that a boundary layer may follow from laminar to turbulent state. The latter is associated with higher drag. Prolonging the laminar boundary can therefore enhance efficiency in applications such as the flow over aircraft. Bypass transition is caused by the growth of streaks of low and high velocity in the laminar boundary.Spanwise arrays of plasma actuators have shown promise in experimental demonstrations of the active cancelation of these streaks in an open-loop and also closed-loop feedback control framework to delay transition in the past. However, when the plasma actuators were given a step input to model a fast response to a detected streak, a non-minimum phase response of the far-field velocity and shear stress was detected. Experiments were limited to only the streamwise velocity component and to regions considered in the far fields given physical sensor limitations.

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“…The pressure difference caused by the low pressure of the vortices and the high pressure in front of the aircraft is the form drag. By installing the after plate on the fuselage rear body, the vortex generated by the after plate can effectively control the airflow separation and vortices in the fuselage rear body flow field, and achieve the purpose of reducing the form drag [6]. The layout of the after plate is shown in Figure 4.…”

Section: Study On the Influence Of After Plate On Form Dragmentioning

confidence: 99%

Study on Optimization of Drag Characteristics of Large Civil Airliners

Lu¹,

Zhao²,

Wang³

2019

dtcse

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In order to reduce the drag of large civil airliners and improve the economy of their operation, this paper chooses the shape of a typical large civil airliner as the research object, analyses the causes and classifications of the drag of large civil airliners, and puts forward the drag reduction measures for different sources of drag by means of numerical simulation. The results show that the frictional drag can be reduced by installing vortex generator on the rear body of the fuselage, the form drag can be significantly reduced by installing the after body end plate, improving high angle of Attack Performance and the induced drag can be further reduced by using the vertical section add to the lateral section of the winglets. The results can lay a theoretical foundation for aerodynamic shape design and optimization of large civil airliners.

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Attenuation of Tollmien–Schlichting Waves Using Plasma Actuator Vortex Generators

Cited by 23 publications

References 16 publications

Control of crossflow-vortex-induced transition by unsteady control vortices

Control of crossflow-vortex-induced transition by unsteady control vortices

Laminar Boundary-Layer Response to Step Input by an Array of Plasma Actuators

Study on Optimization of Drag Characteristics of Large Civil Airliners

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