Closed-Loop Stall Control System

Poggie, Jonathan; Tilmann, Carl P.; Flick, Peter; Silkey, Joseph; Osbourne, Bradley A.; Ervin, Gregory; Maric, D.S.; Mangalam, S. M.; Mangalam, Arun S.

doi:10.2514/1.c000262

Cited by 28 publications

(15 citation statements)

References 9 publications

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“…2 Active flow control is also well-suited for use with feedback controllers, and the successful integration of these technologies has been demonstrated in various aerodynamic systems. [3][4][5][6][7][8][9] The periodic excitation used for active flow control is often generated using oscillatory momentum devices that produce zero-net mass flux. 10 Momentum can be introduced by a variety of techniques, but the most common ones are piezoelectric, electromagnetic and electrostatic.…”

mentioning

confidence: 99%

“…These sensors can be used to identify the various critical points in the shear stress field and have recently been implemented in AC-DBD plasma feedback control studies of lift enhancement. 7 Two types of control systems are investigated. The first is a very simple on/off type controller that operates based on a mean hot film signal value threshold for static Re conditions.…”

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confidence: 99%

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Flow Separation Control over an Airfoil with Nanosecond Pulse Driven DBD Plasma Actuators

Rethmel

Little

Takashima

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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This work continues an ongoing development and use of dielectric barrier discharge (DBD) plasma actuators driven by repetitive nanosecond pulses for high Reynolds number aerodynamic flow control. These actuators are believed to influence the flow via a thermal mechanism which is fundamentally different from the more commonly studied AC-DBD plasmas. Leading edge separation control on an 8-inch chord NACA 0015 airfoil is demonstrated at various post-stall angles of attack (α) for Reynolds numbers (Re) and Mach numbers (M) up to 1.15x10 6 and 0.26 respectively (free stream velocity, U ∞ = 93 m/s). The nanosecond pulse driven DBD can extend the stall angle at low Re by functioning as an active trip. At poststall α, the device generates coherent spanwise vortices that transfer momentum from the freestream to the separated region, thus reattaching the flow. This is observed for all Re and M spanning the speed range of the subsonic tunnel used in this work. The actuator is also integrated into a feedback control system with a stagnation-line-sensing hot film on the airfoil pressure side. A simple on/off type controller that operates based on a threshold of the mean value of the power dissipated by the hot film is developed for this system. A preliminary extremum seeking controller is also investigated for dynamically varying Re. Several challenges typically associated with integration of DBD plasma actuators into a feedback control system have been overcome. The most important of these is the demonstration of control authority at realistic takeoff and landing Re and M. Nomenclature c = model chord, 20.32 cm C L = sectional lift coefficient

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mentioning

confidence: 99%

mentioning

confidence: 99%

Flow Separation Control over an Airfoil with Nanosecond Pulse Driven DBD Plasma Actuators

Rethmel

Little

Takashima

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…As a consequence, some authors already use this kind of measurements as an input of closed-loop flow separation control scheme. Poggie et al 11 use hot-film sensors to follow the separation line which moves upstream from the trailing edge of a flap as its deflection angle increases. The closedloop strategy is as follows.…”

Section: Introductionmentioning

confidence: 99%

Experimental Detection and Pulsed Jets Control of Turbulent Boundary Layer Separation

Chabert¹,

Dandois²,

Garnier³

et al. 2012

6th AIAA Flow Control Conference

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Wind tunnel experiments are conducted to investigate the effect of constant and periodic blowing on flow separation from a non-slotted NACA-type flap which is equipped with seven pulsed jets actuators and tested at Re 10 6 through different deflection angles from 2 to 35 • . Laser beam tomoscopy is first used to visualize flow structures with and without flow control. The recirculation zone length is mainly estimated by means of wall shear stress measurements provided by hot-film gauges which are chordwise distributed on the flap. Two separation criteria based on higher-order statistical moments are proposed to detect the flow separation location. They are practised in the uncontrolled, constant blowing and periodic blowing cases. The two criteria are finally applied to follow the open-loop response of the system and determine the system static map local gradient in an attempt to evaluate the feasibility of extremum-seeking approach of closed-loop control.

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“…Among these actuators, those based on dielectric barrier discharges (DBDs) have become increasingly popular because of their effectiveness. Figure 1(a), taken from Poggie et al (2010), shows a typical configuration. In the figure, the purple glow reveals the presence of plasma under actuator operation.…”

Section: Introductionmentioning

confidence: 99%

Multi-fluid modelling of pulsed discharges for flow control applications

Poggie

2015

International Journal of Computational Fluid Dynamics

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Experimental evidence suggests that short-pulse dielectric barrier discharge actuators are effective for speeds corresponding to take-off and approach of large aircraft, and thus are a fruitful direction for flow control technology development. Largeeddy simulations have reproduced some of the main fluid dynamic effects. The plasma models used in such simulations are semi-empirical, however, and need to be tuned for each flowfield under consideration. In this paper, the discharge physics is examined in more detail with multi-fluid modelling, comparing a five-moment model (continuity, momentum, and energy equations) to a two-moment model (continuity and energy equations). A steady-state, one-dimensional discharge was considered first, and the five-moment model was found to predict significantly lower ionisation rates and number densities than the two-moment model. A two-dimensional, transient discharge problem with an elliptical cathode was studied next. Relative to the two-moment model, the five-moment model predicted a slower response to the activation of the cathode, and lower electron velocities and temperatures as the simulation approached steady-state. The primary reason for the differences in the predictions of the two models can be attributed to the effects of particle inertia, particularly electron inertia in the cathode layer. The computational cost of the five-moment model is only about twice that of the simpler variant, suggesting that it may be feasible to use the more sophisticated model in practical calculations for flow control actuator design.

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Closed-Loop Stall Control System

Cited by 28 publications

References 9 publications

Flow Separation Control over an Airfoil with Nanosecond Pulse Driven DBD Plasma Actuators

Flow Separation Control over an Airfoil with Nanosecond Pulse Driven DBD Plasma Actuators

Experimental Detection and Pulsed Jets Control of Turbulent Boundary Layer Separation

Multi-fluid modelling of pulsed discharges for flow control applications

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