Synthesis of a Variable Geometry Trailing Edge Control Surface

2003 ◽  
Author(s):  
Edwin Forster ◽  
Brian Sanders ◽  
Frank Eastep
Keyword(s):  
Control Surface ◽  
Variable Geometry ◽  
Trailing Edge

A Hybrid Morphing Trailing Edge Designed for Camber Change of the Control Surface

2016 ◽  
Author(s):  
Ilhan Ozan Tunçöz ◽  
Yosheph Yang ◽  
Ercan Gürses ◽  
Melin Sahin ◽  
Yavuz Yaman ◽  
...  
Keyword(s):  
Control Surface ◽  
Trailing Edge

Modeling and Testing of a Seamless Wing Trailing Edge Control Actuation System

2012 ◽  
Vol 195-196 ◽  
pp. 1089-1094
Author(s):  
Yuan Yuan He ◽  
Li Liu
Keyword(s):  
Numerical Model ◽  
Physical Properties ◽  
Control Surface ◽  
Vibration Test ◽  
Structural System ◽  
Trailing Edge ◽  
Modeling And Analysis ◽  
Actuation Mechanism ◽  
Actuation System ◽  
System Vibration

This paper presents an investigation into the modeling and analysis of an innovative actuation system for a wing with a seamless flexible trailing edge control surface. Research was started with the study of aerodynamic behavior and advantage of the wing in smooth variable chamber shape under control. Based on the concept and design, an experimental wing section integrated with the actuation mechanism was built and tested. The main effort was then made to the modeling of the internal actuation system for the purpose of obtaining the physical properties and accurate modeling of the whole wing structural system. To validate and update the numerical model of the system, vibration test of the actuation system including the mechanism and actuator was carried out. Some key parameters such as the stiffness of the actuation system were identified from vibration test data. The investigation demonstrated a practical approach to quantify some key parameters and update the numerical model of an actuation system.

The Dassault Mirage G

1969 ◽  
Vol 73 (708) ◽  
pp. 1027-1028
Author(s):  
Henri Deplante
Keyword(s):  
Leading Edge ◽  
Variable Geometry ◽  
Relative Thickness ◽  
Trailing Edge ◽  
High Lift ◽  
Profound Knowledge ◽  
Subsonic Speed ◽  
Trailing Edge Flaps ◽  
Leading Edge Slats

The interest of wings with variable sweepback springs directly from pure commonsense and appeals to no profound knowledge of aerodynamics for its justification. To realise the advantage of variable geometry, it is enough to know that only a wing of small relative thickness is capable of good performance at supersonic speeds and that by increasing the sweepback from 20° to 70° the thickness of a wing is divided by about 2. In the advanced position, the wing offers its full span to the airstream and with high-lift devices in action (leading-edge slats and trailing-edge flaps combined), the aeroplane can develop the considerable lift necessary for take-off and landing as well as for break-through and for slow approach. Wings still advanced but slats, flaps and undercarriage retracted, the aeroplane is in excellent maximum fineness condition for protracted cruising at subsonic speed or for a long wait. As soon as transonic (Mach No of more than 0-8) or supersonic speeds are in question, the wings are progressively folded back.

scholarly journals IMPACT OF VARIABLE GEOMETRY MINIFLAPS ON SAILPLANE FLIGHT CHARACTERISTICS

Aviation ◽  
2017 ◽  
Vol 21 (4) ◽  
pp. 119-125
Author(s):  
Peep LAUK ◽  
Karl-Erik SEEGEL ◽  
Toivo TÄHEMAA
Keyword(s):  
Aerodynamic Drag ◽  
Variable Geometry ◽  
Wing Loading ◽  
Wing Area ◽  
Trailing Edge ◽  
Standard Atmosphere ◽  
Flight Parameters

Miniflaps (also known as mini-TED, active Gurnay flaps, etc.) located at the wing trailing edge enable to increase wing lift and reduce the aerodynamic drag. Variable geometry miniflaps (VGMF) elaborated at the Estonian Aviation Academy enable to expand the wing area up to 6.5%, when extended, and, at the same time, deflect 16.7 degrees downwards. The use of VGMF is especially promising for reducing the airspeed and sink speed of modern high wing loading sailplanes flying in thermals. The VGMFs were built in cooperation with the Lithuanian company JSC “Sportine Aviacija ir Ko”. They were fixed inside the sailplane LAK-17B trailing flaps. During the test flights, the VGMF effect on the sailplane’s sink speed was measured at different airspeeds and different flap positions. The flight parameters were recorded electronically and later calculated for standard atmosphere. The method of parallel flight was used for comparison. The results indicate that with the flaps position at + 9 degrees, the CAS 79.5 km/h sink speed decreased 0.775–0.555  m/s, i.e. 39.6%. The sailplane’s wing loading was 39.4 kg/m 2. With the flaps position at + 15 degrees, the optimal airspeed decreased, but the sink speed, compared to the previous, rose. Cl max increased with the VGMF 1.41–1.58 (i.e. 12%).

scholarly journals Improved aerostructural performance via aeroservoelastic tailoring of a composite wing

2018 ◽  
Vol 122 (1255) ◽  
pp. 1442-1474 ◽  
Author(s):  
Eduardo P. Krupa ◽  
Jonathan E. Cooper ◽  
Alberto Pirrera ◽  
Raj Nangia
Keyword(s):  
Control Surface ◽  
Aerodynamic Load ◽  
Trailing Edge ◽  
Aeroelastic Tailoring ◽  
Fuel Burn ◽  
Shape Adaptation ◽  
Trade Offs ◽  
Trailing Edge Flaps ◽  
Gradient Based ◽  
Composite Wing

ABSTRACTThis paper investigates the synergies and trade-offs between passive aeroelastic tailoring and adaptive aeroelastic deformation of a transport composite wing for fuel burn minimisation. This goal is achieved by optimising thickness and stiffness distributions of constitutive laminates, jig-twist shape and distributed control surface deflections through different segments of a nominal “cruise-climb” mission. Enhanced aerostructural efficiency is sought both passively and adaptively as a means of aerodynamic load redistribution, which, in turn, is used for manoeuvre load relief and minimum drag dissipation. Passive shape adaptation is obtained by embedding shear-extension and bend-twist couplings in the laminated wing skins. Adaptive camber changes are provided via full-span trailing-edge flaps. Optimised design solutions are found using a bi-level approach that integrates gradient-based and particle swarm optimisations in order to tailor structural properties at rib-bay level and retrieve blended stacking sequences. Performance benefits from the combination of passive aeroelastic tailoring with adaptive control devices are benchmarked in terms of fuel burn and a payload-range efficiency. It is shown that the aeroservoelastically tailored composite design allows for significant weight and fuel burn improvements when compared to a similar all-metallic wing. Additionally, the trailing-edge flap augmentation can extend the aircraft performance envelope and improve the overall cruise span efficiency to nearly optimal lift distributions.

Structural and acoustic noise produced by turbulent flow over an elastic trailing edge

1993 ◽  
Vol 442 (1916) ◽  
pp. 533-554 ◽  
Keyword(s):  
Turbulent Flow ◽  
Elastic Plate ◽  
Acoustic Noise ◽  
Acoustic Radiation ◽  
Steel Plates ◽  
Control Surface ◽  
Secondary Source ◽  
Thin Elastic Plate ◽  
Mean Flow ◽  
Trailing Edge

An analysis is made of the sound and vibration produced by turbulent flow at low Mach number over the trailing edge of an elastic plate. The trailing edges of airfoils and other flow control surfaces are known to be important sources of high frequency sound. When the surface is compliant the turbulent edge-flow also excites structural modes of vibration. In conditions of heavy fluid loading, which typically occurs in underwater applications, the energy imparted to the structural motions can be large, and the subsequent scattering of ‘surface waves’ at mechanical discontinuities is frequently an important secondary source of sound. In this paper general formulae are developed for the structural and acoustic edge-noise when the control surface is modelled by a semi-infinite, thin elastic plate which can support bending waves. Numerical results are given for steel plates in air and in water. In the latter case it is shown that, when the frequency is smaller than the coincidence frequency the bending wave power exceeds the total sound power generated at the edge by 20–40 dB, independently of the mean flow velocity, so that sound generated by secondary scattering may then be the dominant source of acoustic radiation.

Characterization of typical aeroelastic sections under combined structural concentrated nonlinearities

2021 ◽  
pp. 107754632110001
Author(s):  
José Augusto I da Silva ◽  
Flávio D Marques
Keyword(s):  
Time Integration ◽  
Unsteady Aerodynamics ◽  
Nonlinear Effects ◽  
Free Play ◽  
Control Surface ◽  
Trailing Edge ◽  
Aeroelastic System ◽  
Practical Applications ◽  
Structural Nonlinearities ◽  
The Stability

Structural nonlinearities are usually present in aeroelastic systems. The analysis of this system commonly comprises a study involving only one type of nonlinearity, influencing a particular motion of the airfoil. However, practical applications of aeroelastic systems can be affected by different types of structural nonlinearities. It becomes essential to study the stability of the aeroelastic system under these conditions to assess more real operational flight procedures. In this context, this article presents an investigation of a typical aeroelastic section response with trailing edge control surface subjected to combinations of concentrated structural nonlinearities. Different nonlinear scenarios involving cubic hardening stiffness in pitching and free play, free play with preload, and slip dry friction in the trailing edge control surface motion are analyzed. The mathematical model is based on linear unsteady aerodynamics coupled to a three-dof typical aeroelastic section. Hopf bifurcations diagrams are obtained from direct time integration of the equation of motion. The post-flutter limit cycle oscillations are investigated, revealing supercritical and subcritical bifurcations. A complete parametric study of the nonlinear parameters is carried out, thereby allowing a sensitivity analysis of each nonlinear scenario. The results show that aeroelastic tailoring considering the mild post-flutter behavior can be achieved through an appropriate choice of combined nonlinear effects. Moreover, combined nonlinearities can mitigate the undesired subcritical aeroelastic responses caused by free play.

scholarly journals Experimental Performance in Annular Cascade of Variable Trailing-Edge Flap, Axial-Flow Compressor Inlet Guide Vanes

1970 ◽  
Author(s):  
T. H. Okiishi ◽  
G. H. Junkhan ◽  
G. K. Serovy
Keyword(s):  
Guide Vane ◽  
Axial Flow ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Trailing Edge ◽  
Axial Flow Compressor ◽  
Compressor Inlet ◽  
Trailing Edge Flap ◽  
Flow Compressor ◽  
Annular Cascade

Aerodynamic performance of a variable-geometry axial-flow compressor inlet guide vane configuration for a gas turbine unit was determined in a series of annular cascade tests. The variable-geometry vanes used uncambered, symmetrical airfoil sections as the basic blade profile with the rear 70 percent of the vane profile movable as a trailing-edge flap. Vane flap mechanical setting angles of 0 to 50 deg measured from the axial direction were possible, and performance parameters were determined over this range of angles. Turning angles followed a general trend obtained with Carter’s rule for accelerating cascades with the presently measured values tending to be lower than those obtained with Carter’s rule at higher setting angles. For large camber angles (greater than 35 deg) zero-incidence blade element total-pressure loss coefficients for the 50 percent passage location of the flapped vanes tested were higher than those that might have been obtained with a continously cambered vane row of the same solidity and camber.

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