A Numerical Study on the Ability of Shock Control Bumps for Buffet Alleviation

Mayer, R.; Lutz, Thorsten; Kraemer, Ewald

doi:10.2514/6.2017-0711

Cited by 6 publications

(8 citation statements)

References 29 publications

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“…According to Mayer [6], the smooth transition leads to isentropic compressions waves and might perform better whilst the kink anchor with a wedge-shaped bump is more robust towards flow condition changes [61]. However, the SCB height, position as well as the location of the crest are very important for an effective and robust bump design [27,55,59,60]. This is why an accurate control of the SCB should be enabled by an adaptive system.…”

Section: Literature Review Of Adaptive Concepts For Shock Controlmentioning

confidence: 99%

“…The goals of shock control are to implement a device which reduces the shock strength and consequently wave drag and/or to delay the buffet onset and thus to reduce emissions, extend the flight envelop and/or reduce flow induced vibrations. While the drag reduction potential of SCBs has been investigated over almost the past three decades [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25], buffet control by SCBs has been investigated less extensively [6][7][8][9][26][27][28][29]. For detailed research on buffet control via SCBs the reader is referred to Mayer [6] and Mayer et al [7].…”

Section: Introductionmentioning

confidence: 99%

“…Adaptive SCBs are one type of morphing wing technologies [32][33][34][35][36][37][38][39][40][41] which also include, e.g., morphing leading edges (droop nose) [42][43][44][45][46][47][48], morphing trailing edges [30,[49][50][51] or morphing winglets [50,52]. In addition to two-dimensional (2D) bumps, the potential of three-dimensional (3D) SCBs for reducing drag and/or delaying buffet onset has been investigated [6,7,22,26,27,[53][54][55][56][57]. A comparison between 2D and 3D bumps is given by Deng and Qin [58].…”

Section: Introductionmentioning

confidence: 99%

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Review of Adaptive Shock Control Systems

et al. 2021

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Drag reduction plays a major role in future aircraft design in order to lower emissions in aviation. In transonic flight, the transonic shock induces wave drag and thus increases the overall aircraft drag and hence emissions. In the past decades, shock control has been investigated intensively from an aerodynamic point of view and has proven its efficacy in terms of reducing wave drag. Furthermore, a number of concepts for shock control bumps (SCBs) that can adapt their position and height have been introduced. The implementation of adaptive SCBs requires a trade-off between aerodynamic benefits, system complexity and overall robustness. The challenge is to find a system with low complexity which still generates sufficient aerodynamic improvement to attain an overall system benefit. The objectives of this paper are to summarize adaptive concepts for shock control, and to evaluate and compare them in terms of their advantages and challenges of their system integrity so as to offer a basis for robust comparisons. The investigated concepts include different actuation systems as conventional spoiler actuators, shape memory alloys (SMAs) or pressurized elements. Near-term applications are seen for spoiler actuator concepts while highest controllability is identified for concepts several with smaller actuators such as SMAs.

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Section: Literature Review Of Adaptive Concepts For Shock Controlmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Review of Adaptive Shock Control Systems

et al. 2021

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“…This sizing constraint is more difficult to achieve when considering SCBs already within a buffeting flow as the height and extent of the boundary layer varies across a shock oscillation cycle. More recently, Mayer et al [22] suggested that in terms of SCBs (wedge-type) for buffet control, the buffet behaviour was relatively insensitive to bump crest height. Further, Tian et al [24] demonstrated buffet suppression in 2D with contour like SCBs using heights of h b /c = 0.008 and 0.01; however, there are no definitive relationships between bump crest height and buffet suppression performance.…”

Section: Case 3: Impact Of Scb Crest Heightmentioning

confidence: 99%

“…Contour-bumps, alternatively, are usually described by a smooth, continuous surface deformation (relative to wedge-bumps). The efficacy of these geometries is still contested in terms of their performance in drag reduction in pre-buffet conditions; however, both approaches seem to offer either alleviation in 2D/3D [22,23] or complete suppression in 2D [24] in on-design conditions. Given that these devices inherently must be designed for a particular flight condition for optimal performance, the impact of a fixed SCB on a wing can often lead to diminished off-design performance relative to the clean wing configuration.…”

Section: Introductionmentioning

confidence: 99%

A Numerical Investigation of the Geometric Parametrisation of Shock Control Bumps for Transonic Shock Oscillation Control

Geoghegan

Giannelis

Vio

2020

Fluids

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At transonic flight conditions, shock oscillations on wing surfaces are known to occur and result in degraded aerodynamic performance and handling qualities. This is a purely flow-driven phenomenon, known as transonic buffet, that causes limit cycle oscillations and may present itself within the operational flight envelope. Hence, there is significant research interest in the development of shock control techniques to either stabilise the unsteady flow or raise the boundary onset. This paper explores the efficacy of dynamically activated contour-based shock control bumps within the buffet envelope of the OAT15A aerofoil on transonic flow control numerically through unsteady Reynolds-averaged Navier–Stokes modelling. A parametric evaluation of the geometric variables that define the Hicks–Henne-derived shock control bump will show that bumps of this type lead to a large design space of applicable shapes for buffet suppression. Assessment of the flow field, local to the deployed shock control bump geometries, reveals that control is achieved through a weakening of the rear shock leg, combined with the formation of dual re-circulatory cells within the separated shear-layer. Within this design space, favourable aerodynamic performance can also be achieved. The off-design performance of two optimal shock control bump configurations is explored over the buffet region for M = 0.73, where the designs demonstrate the ability to suppress shock oscillations deep into the buffet envelope.

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Numerical analysis of shock characteristics control based on bump

Wang

et al. 2023

Fluid Dyn. Res.

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The effects of bump control on shock aerodynamic characteristics have been investigated by simulations. A bump control that based on the changes of local upper surface of 2D airfoil or 3D wing model has been used to affect the shock intensity and position. The simulation results are close of other experiment when the calculate parameters are the same. The simulations show that the drag and lift characteristics can be improved with the bump control, and the results of improvement strongly depend on control parameters. For the two-dimensional RAE2822 airfoil, the optimal control position of the bump control must be close to the position of the shock wave. The 3D local bump that located on 80% wing span wise and closed to tip can acquire a batter control results for the 3D RAE2822 wing model.

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A Numerical Study on the Ability of Shock Control Bumps for Buffet Alleviation

Cited by 6 publications

References 29 publications

Review of Adaptive Shock Control Systems

Review of Adaptive Shock Control Systems

A Numerical Investigation of the Geometric Parametrisation of Shock Control Bumps for Transonic Shock Oscillation Control

Numerical analysis of shock characteristics control based on bump

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