ACTIVE WING FLUTTER SUPPRESSION USING A TRAILING EDGE FLAP

2002 ◽  
Vol 16 (3) ◽  
pp. 271-294 ◽  
Author(s):  
D. BORGLUND ◽  
J. KUTTENKEULER
2019 ◽  
Vol 52 (1-2) ◽  
pp. 81-90 ◽  
Author(s):  
Ting-Rui Liu

Modeling of aeroelastic system of wind turbine blade section based on chordwise rigid trailing-edge flap has been investigated. The flutter suppression of blade section exhibiting flap-wise bending and twist deformation is performed by equivalent sliding mode control. Aerodynamic expressions are based on the modified quasi-steady model which is attached to the influences of trailing-edge flap. The continuous equivalent sliding mode control algorithm based on quadratic feedback parameter is applied to realize flutter suppression, with displacements and velocities, control input of angle of trailing-edge flap and sliding mode function demonstrated. To facilitate the process of computer implementation, the discrete equivalent sliding mode control algorithm is discussed in detail, with better control effects and angle control of trailing-edge flap demonstrated. The quadratic feedback–based equivalent sliding mode control algorithm, including continuous equivalent sliding mode control and discrete equivalent sliding mode control, realizes the analysis of control effects based on feedback parameter with empirical adjustment coefficient. This provides schemes of not only theoretical simulation but also real-time implementation for the application of equivalent sliding mode control in different engineering projects.


2021 ◽  
pp. 002029402098337
Author(s):  
Ting-Rui Liu ◽  
Ai-Ling Gong

Vibration and control of cantilever blade with bending-twist coupling (BTC) based on trailing-edge flap (TEF) by restricted control input are investigated. The blade is a thin-walled structure using circumferentially asymmetric stiffness (CAS) configuration, with TEF embedded and hinged into the host composite structure along the entire blade span. The TEF structure is driven by quasi-steady aerodynamic forces. Vibration control is investigated based on linear matrix inequation (LMI) algorithm using restricted control input (LMI/RCI). Flutter suppression of BTC displacements and the angle of TEF (i.e. the practical control input) are illustrated, with apparently controlled effects demonstrated. The restricted control input signals are used to driven the TEF to explore the scope of the feasibility of the practical TEF angle, which is displayed by a virtual simulation platform. The platform verifies the feasibility of the hardware implementation for the control algorithms.


2001 ◽  
Vol 105 (1049) ◽  
pp. 391-399 ◽  
Author(s):  
W. Chan ◽  
A. Brocklehurst

Abstract An analytical evaluation of the performance enhancement due to a servo-actuated trailing edge flap was carried out using the coupled rotor-fuselage model (CRFM). The performance enhancement from a trailing edge flap is achieved by introducing effective camber around the azimuth for a nominal aerofoil. An investigation on the best combination of flap parameters, namely the span, position, chord and deflection was carried out in order to identify an optimal configuration within given design constraints. The effects on vibratory control loads over a range of speed for a flap of 10% span, 20% chord, actuated at once per rev has expanded the retreating blade envelope for a Lynx aircraft by some 20kt. The flap hinge load was also examined and it was found not to be excessive. It was also confirmed that an actuated trailing edge flap does not have adverse effect on the pilot's control inputs to trim to a particular flight condition. This paper will discuss the aerodynamic enhancements derived from the application of the trailing edge flap and present conclusions drawn from this study.


2018 ◽  
Vol 55 (1) ◽  
pp. 382-389 ◽  
Author(s):  
Y. Tian ◽  
Z. Li ◽  
P. Q. Liu

2018 ◽  
Vol 141 (6) ◽  
Author(s):  
V. Tremblay-Dionne ◽  
T. Lee

The effect of trailing-edge flap (TEF) deflection on the aerodynamic properties and flowfield of a symmetric airfoil over a wavy ground was investigated experimentally. This Technical Brief is a continuation of Lee and Tremblay-Dionne (2018, “Experimental Investigation of the Aerodynamics and Flowfield of a NACA 0015 Airfoil Over a Wavy Ground,” ASME J. Fluids Eng., 140(7), p. 071202) in which an unflapped airfoil was employed. Regardless of the flap deflection, the cyclic variation in the sectional lift Cl and pitching moment Cm coefficients over the wavy ground always persists. The Cm also has an opposite trend to Cl. The flap deflection, however, produces an increased maximum and minimum Cl and Cm with a reduced fluctuation compared to their unflapped counterparts. The Cd increase outperforms the Cl increase, leading to a lowered Cl/Cd of the flapped airfoil.


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