Active cancellation of Tollmien–Schlichting instabilities on a wing using multi-channel sensor actuator systems

Sturzebecher, D.; Nitsche, W.

doi:10.1016/s0142-727x(03)00051-1

Cited by 78 publications

(47 citation statements)

References 12 publications

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“…Modern developments in robust control theory may be used to rigourously incorporate uncertainties in the design process during the modelling step (see, e.g., Hervé et al 2012) or by introducing adaptive controllers (see, e.g., Sturzebecher & Nitsche 2003). The parametric analysis proposed in this work clearly suggests that a careful analysis of the actuation, based on both linear and nonlinear simulations, is helpful to determine the main parameters characterizing the geometry of a fully threedimensional configuration.…”

Section: Discussionmentioning

confidence: 97%

“…The extension of our previous work is not trivial due to the three-dimensional, localized nature of the control action. The necessity of introducing localized actuators is a constraint often found in experimental configurations and can represent a first limitation of the control design; considering the TS instabilities, applications can be found in the experimental works by Sturzebecher & Nitsche (2003) and Li & Gaster (2006). For the bypass transition and the associated streak growth, the reader can refer to the experimental analysis carried out by Lundell (2007) and Monokrousos et al (2008).…”

mentioning

confidence: 99%

“…Our choice of model for the actuators and sensors as localized volume forcing is relevant for practical implementations. Examples are provided by the experimental works by Sturzebecher & Nitsche (2003) and Li & Gaster (2006) for control of TS wavepackets. Moreover, the actuator chosen here makes the setup rather close to the action provided on the flow by simple models mimicking plasma actuators (Kriegseis 2011).…”

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confidence: 99%

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Transition delay in a boundary layer flow using active control

et al. 2013

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Active linear control is applied to delay the onset of laminar-turbulent transition in the boundary layer over a flat plate. The analysis is carried out by numerical simulations of the nonlinear, transitional regime. A three-dimensional, localized initial condition triggering Tollmien-Schlichting waves of finite amplitude is used to numerically simulate the transition to turbulence. Linear quadratic Gaussian controllers based on reduced-order models of the linearized Navier-Stokes equations are designed, where the wall sensors and the actuators are localized in space. A parametric analysis is carried out in the nonlinear regime, for different disturbance amplitudes, by investigating the effects of the actuation on the flow due to different distributions of the localized actuators along the spanwise direction, different sizes of the actuators and the effort of the controllers. We identify the range of parameters where the controllers are effective and highlight the limits of the device for high amplitudes and strong control action. Despite the fully linear control approach, it is shown that the device is effective in delaying the onset of laminar-turbulent transition in the presence of packets characterized by amplitudes a ≈ 1 % of the free stream velocity at the actuator location. Up to these amplitudes, it is found that a proper choice of the actuators positively affects the performance of the controller. For a transitional case, a ≈ 0.20 %, we show a transition delay of ∆Re x = 3.0 × 10 5 .

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Section: Discussionmentioning

confidence: 97%

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confidence: 99%

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confidence: 99%

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Transition delay in a boundary layer flow using active control

et al. 2013

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“…Following the work by Fabbiane et al (2015b), localised measurement of the streamwise skin friction are used as sensors in order to model surface hot-wires (Sturzebecher & Nitsche 2003;Li & Gaster 2006;Kurz et al 2013). Each signal is subtracted by its time average over 750 time units in order to remove the mean-flow contribution to the wall stress.…”

Section: Inputs and Outputsmentioning

confidence: 99%

“…In this paper, this transfer function is computed via a linear impulse response of the actuator u l . This transfer function is commonly addressed as the secondary path (Sturzebecher & Nitsche 2003). The secondary path provides the control algorithm with information on how the actuators can affect the flow.…”

Section: Control Strategymentioning

confidence: 99%

Energy efficiency and performance limitations of linear adaptive control for transition delay

2016

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A reactive control technique with localised actuators and sensors is used to delay the transition to turbulence in a flat-plate boundary-layer flow. Through extensive direct numerical simulations, it is shown that an adaptive technique, which computes the control law on-line, is able to significantly reduce skin-friction drag in the presence of random three-dimensional perturbation fields with linear and weakly nonlinear behaviour. An energy budget analysis is performed in order to assess the net energy saving capabilities of the linear control approach. When considering a model of the dielectric-barrier-discharge (DBD) plasma actuator, the energy spent to create appropriate actuation force inside the boundary layer is of the same order as the energy gained from reducing skin-friction drag. With a model of an ideal actuator a net energy gain of three orders of magnitude can be achieved by efficiently damping small-amplitude disturbances upstream. The energy analysis in this study thus provides an upper limit for what we can expect in terms of drag-reduction efficiency for linear control of transition as a means for drag reduction.

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Actuation of an elastic membrane by the use of an electrorheological valve

Schomberg

Gerland

Wünsch

et al. 2021

Proc Appl Math and Mech

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The dynamic response of a fluidic actuator is investigated on the basis of numerical simulations. With this actuator a membrane is excited to oscillate by means of an electrorheological valve. For this purpose the solid and fluid domains are coupled. Furthermore, the constitutive equation of the fluid is coupled to the electric field. The dynamic response is discussed on the example of a variable stiffness of the membrane. Actuators of this type offer the potential to delay the transition of a boundary layer.

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Active cancellation of Tollmien–Schlichting instabilities on a wing using multi-channel sensor actuator systems

Cited by 78 publications

References 12 publications

Transition delay in a boundary layer flow using active control

Transition delay in a boundary layer flow using active control

Energy efficiency and performance limitations of linear adaptive control for transition delay

Actuation of an elastic membrane by the use of an electrorheological valve

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