Stability and Control Investigations of Generic 53 Degree Swept Wing with Control Surfaces

Schütte, Andreas; Huber, Kerstin Claudie; Frink, Neal T.; Boelens, O.J.

doi:10.2514/1.c033700

Cited by 8 publications

(2 citation statements)

References 79 publications

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“…Weak instabilities were observed in some of the flight modes, especially in the sideslip condition, which could be easily controlled by the control effectors. Besides the conventional linear evaluation methods [9], a novel approach of identifying the aerodynamic model from innovative wind tunnel maneuvers was employed for the tailless DLR-F19 configuration [10], [11]. The resulting aerodynamic model was able to capture the highly nonlinear aerodynamic effects and could directly be integrated into the flight dynamics model, which exhibited Dutch-roll mode corresponding to flying qualities worse than level 3.…”

Section: Introductionmentioning

confidence: 99%

An Innovative Experimental Approach to Lateral-Directional Flying Quality Investigation for Tailless Aircraft

Nie¹,

Liu²,

Cen³

et al. 2020

IEEE Access

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Tailless aircraft suffers from limited yaw control power and poor directional stability inherently. To address these issues in the early design process of a tailless configuration with low costs and risks, this paper presents an innovative experimental approach to control law validation and quantitative flying quality evaluation with a dynamically scaled model mounted on a three degree-of-freedom rig in the wind tunnel. The motion equations of the tailless demonstrator on the rig are derived, and then the comparisons of the lateral-directional flight dynamics between the rig constrained model and the free flight model are carried out. Construction of the control augmentation system for yaw and roll motion is accomplished according to the scale modified criteria of flying qualities. Effectiveness of the designed control law is demonstrated with steady pilot-in-the-loop flights at different airspeeds and angles of attack. The achieved closed-loop flying qualities are evaluated by applying multistep maneuvers for low order equivalent system identification. Whereas severe instability is observed in yaw for the open-loop case, the closed-loop flying quality of the Dutch-roll mode can be improved to level 1 at low angle of attack.

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Section: Introductionmentioning

confidence: 99%

An Innovative Experimental Approach to Lateral-Directional Flying Quality Investigation for Tailless Aircraft

Nie¹,

Liu²,

Cen³

et al. 2020

IEEE Access

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“…To use tailless aircraft configurations, some control parameters such as leading edge flap in design process may be used, that requires precise comprehension of control parameters and their limitations (Schütte et al, 2016), especially when non-linear and discontinues behaviour of control tools are considered. Airplane manoeuvrability contributes to more complicated behaviour and control surface effectiveness intensively depends on amplitude and rate of airplane motion.…”

Section: Introductionmentioning

confidence: 99%

The effects of flow separation on a lambda wing aerodynamics

Dadkhah

Masdari

Vaziri

et al. 2019

AEAT

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Purpose In this paper, experimental and numerical results of a lambda wing have been compared. The purpose of this paper is to study the behaviour of lambda wings using a CFD tool and to consider different numerical models to obtain the most accurate results. As far as the consideration of numerical methods is concerned, the main focus is on the evaluation of computational methods for an accurate prediction of contingent leading edge vortices’ path and the flow separation occurring because of the burst of these vortices on the wing. Design/methodology/approach Experimental tests are performed in a closed-circuit wind tunnel at the Reynolds number of 6 × 105 and angles of attack (AOA) ranging from 0 to 10 degrees. Investigated turbulence models in this study are Reynolds Averaged Navior–Stokes (RANS) models in a steady state. To compare the accuracy of the turbulence models with respect to experimental results, sensitivity study of these models has been plotted in bar charts. Findings The results illustrate that the leading edge vortex on this lambda wing is unstable and disappears soon. The effect of this disappearance is obvious by an increase in local drag coefficient in the junction of inner and outer wings. Streamlines on the upper surface of the wing show that at AOA higher than 8 degrees, the absence of an intense leading edge vortex leads to a local flow separation on the outer wing and a reverse in the flow. Research limitations/implications Results obtained from the behaviour study of transition (TSS) turbulence model are more compatible with experimental findings. This model predicts the drag coefficient of the wing with the highest accuracy. Of all considered turbulence models, the Spalart model was not able to accurately predict the non-linearity of drag and pitching moment coefficients. Except for the TSS turbulence model, all other models are unable to predict the aerodynamic coefficients corresponding to AOA higher than 10 degrees. Practical implications The presented results in this paper include lift, drag and pitching moment coefficients in various AOA and also the distribution of aerodynamic coefficients along the span. Originality/value The presented results include lift, drag and pitching moment coefficients in various AOA and also aerodynamic coefficients distribution along the span.

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