Active Gust Load Alleviation by Means of Steady and Dynamic Trailing and Leading Edge Flap Deflections at Transonic Speeds

Ullah, Junaid; Kamoun, Skander; Müller, Jens; Lutz, Thorsten

doi:10.2514/6.2022-1334

Cited by 5 publications

(5 citation statements)

References 9 publications

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“…To counterbalance the effect of the TEF and the gust on 𝐶 𝑊𝑇𝑀 , the LEF deflections are estimated based on the 2D database. As already demonstrated by the authors of the present paper in [32,33], a full control authority of the wing torsional moment is not feasible by the presented approach with dynamic TEF and LEF. A complete compensation of the WTM loads requires LEF deflections up to 29 • , see second data line in Table 1.…”

Section: B Proof Of Validity For Agla Conceptmentioning

confidence: 76%

“…This can be realized by pre-deflected steady flaps as presented in [32] or during the gust interaction by adapting the dynamic flap deflections The LEF deflection angles as they result with this new approach of limited LEF deflections lead to a maximum in 𝜂 𝐿𝐸𝐹 of 16.8 • , see third data line in Table 1. The limited LEF deflections still affect the TEF deflections noticeably, however the control of the spanwise 𝐶 𝐿 and thus 𝐶 𝑊𝐵𝑀 is predominantly determined by the TEF deflections.…”

Section: B Proof Of Validity For Agla Conceptmentioning

confidence: 99%

“…This means that the benefit of a spanwise load redistribution is deliberately ignored. Recent studies by the author of the paper at hand [32] have shown that a combination of both initial steady flap deflections and superimposed dynamic flap deflections are superior when compared to the individual approaches. While the first introduces a beneficial load redistribution towards the inboard wing the second further reduces the loads during the direct gust interaction.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Approach for Aerodynamic Gust Load Alleviation by Means of Spanwise-Segmented Flaps

Ullah¹,

Lutz²,

Klug³

et al. 2023

Journal of Aircraft

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Active gust load alleviation techniques exhibit a high potential in significantly reducing the transient gust loads on aircraft. In this work the aerodynamic potential of trailing-edge flaps and leading-edge flaps is numerically studied with the purpose to significantly reduce the structural gust loads. The utilized spanwise-segmented flaps represent slight modifications of existing devices for high-lift and maneuvering. The investigations based on unsteady Reynolds-averaged Navier–Stokes computations are conducted by employing a generic wing–fuselage aircraft configuration at transonic flow conditions. Idealized discrete “[Formula: see text]”-type vertical gusts that are relevant for the certification process are used as representative atmospheric disturbances. The focus of this paper is to introduce a practicable prediction method for required trailing- and leading-edge flap deflections for a significant mitigation of gust-induced wing loads. The three-dimensional flap deflections are determined by parametric two-dimensional simulations at representative wing sections. Different extensions of the estimation approach are investigated to assess the influence of the wing planform, the finite wing span, the aerodynamic phase lags, and the flap scheduling. It is shown that the trailing- and leading-edge flaps are promising in terms of alleviation of gust-induced wing bending and wing torsional moments, respectively. However, at high leading-edge flap deflections that are necessary for a full compensation of the wing torsional moment large-scale flow separation is identified. The introduced gust load alleviation approach indicates a good transferability between two-dimensional airfoil and three-dimensional wing aerodynamics for unsteady flap deflections.

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Section: B Proof Of Validity For Agla Conceptmentioning

confidence: 76%

Section: B Proof Of Validity For Agla Conceptmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Approach for Aerodynamic Gust Load Alleviation by Means of Spanwise-Segmented Flaps

Ullah¹,

Lutz²,

Klug³

et al. 2023

Journal of Aircraft

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“…The control surface layout of the DLR LEISA configuration is derived from the multifunctional control surfaces of the Pro-HMS project [15] and transferred to the DLR LEISA configuration in the work of Ullah et al [13], [14]. Furthermore, the underlying baseline computational grid, used in this work, is described in [13].…”

Section: Numerical Setupmentioning

confidence: 99%

“…These findings are used to assess whether the modeling of the flap deflections by means of the pure grid deformation is sufficient or whether the consideration of the spanwise gaps is elementary important. The studies will be performed on the generic wing fuselage DLR LEISA configuration used in [13] and [14].…”

Section: Introductionmentioning

confidence: 99%

Investigation of a Realistic Flap Modeling Using a Combination of Chimera Method and Grid Deformation on a Wing Fuselage Configuration

Hillebrand

Müller

Ullah

et al. 2023

Proc Appl Math and Mech

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Flap deflections of an aircraft wing for active load alleviation within CFD simulations are realized using pure grid deformation due to time saving and low modeling complexity. In this case, spanwise gaps are neglected, which are present in reality during a flap deflection. Another possibility to realize the deflections is the combination of pure grid deformation and Chimera method, which allows the modeling of the gap between flap and wing or consecutive flaps. The overall aim of this work is the analysis of the aerodynamic effects caused by the different modeling approaches realizing leading and trailing edge flap deflections. The comparison of the modeling methods is investigated on the DLR LEISA configuration, which is a generic wing‐fuselage configuration. For active gust load alleviation, the leading edge flaps are deflected downward and the trailing edge flaps are deflected upward. Due to the downward deflection of the leading edge flaps, vortices are formed using the combined Chimera method as a result of the gap consideration. These vortices lead to a local drag increase resulting in a difference between both modeling methods in the spanwise as well as global drag coefficient. With the pure grid deformation these vortices do not occur. Due to the upward trailing edge deflection, the combined Chimera method leads to a pressure compensation via the effective gap enlargement, which is not present in the pure grid deformation. Overall, the combined Chimera method offers a good possibility to model the induced drag as well as the pressure compensation at a large flap deflection.

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On the Effects of Wing-Gust Interactions and Wing Flap Deflections on the HTP Aerodynamics

Ullah,

Hillebrand,

Ehrle

et al. 2024

High Performance Computing in Science and Engineering '22

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Active Gust Load Alleviation by Means of Steady and Dynamic Trailing and Leading Edge Flap Deflections at Transonic Speeds

Cited by 5 publications

References 9 publications

Approach for Aerodynamic Gust Load Alleviation by Means of Spanwise-Segmented Flaps

Approach for Aerodynamic Gust Load Alleviation by Means of Spanwise-Segmented Flaps

Investigation of a Realistic Flap Modeling Using a Combination of Chimera Method and Grid Deformation on a Wing Fuselage Configuration

On the Effects of Wing-Gust Interactions and Wing Flap Deflections on the HTP Aerodynamics

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