scholarly journals Analysis and Design of a Leading Edge with Morphing Capabilities for the Wing of a Regional Aircraft—Gapless Chord- and Camber-Increase for High-Lift Performance

2021 ◽  
Vol 11 (6) ◽  
pp. 2752
Author(s):  
Conchin Contell Asins ◽  
Volker Landersheim ◽  
Dominik Laveuve ◽  
Seiji Adachi ◽  
Michael May ◽  
...  
Keyword(s):  
Leading Edge ◽  
Bird Strike ◽  
High Lift ◽  
Analysis And Design ◽  
Actuation System ◽  
Aerodynamic Properties ◽  
Reinforced Plastic ◽  
Stall Angle ◽  
Carbon Fibre Reinforced Plastic ◽  
Electromechanical Actuation

In order to contribute to achieving noise and emission reduction goals, Fraunhofer and Airbus deal with the development of a morphing leading edge (MLE) as a high lift device for aircraft. Within the European research program “Clean Sky 2”, a morphing leading edge with gapless chord- and camber-increase for high-lift performance was developed. The MLE is able to morph into two different aerofoils—one for cruise and one for take-off/landing, the latter increasing lift and stall angle over the former. The shape flexibility is realised by a carbon fibre reinforced plastic (CFRP) skin optimised for bending and a sliding contact at the bottom. The material is selected in terms of type, thickness, and lay-up including ply-wise fibre orientation based on numerical simulation and material tests. The MLE is driven by an internal electromechanical actuation system. Load introduction into the skin is realised by span-wise stringers, which require specific stiffness and thermal expansion properties for this task. To avoid the penetration of a bird into the front spar of the wing in case of bird strike, a bird strike protection structure is proposed and analysed. In this paper, the designed MLE including aerodynamic properties, composite skin structure, actuation system, and bird strike behaviour is described and analysed.

scholarly journals Increase in high-lift devices efficiency of swept wing

2020 ◽  
Vol 23 (6) ◽  
pp. 101-120
Author(s):  
Yu. S. Mikhailov
Keyword(s):  
Lift Coefficient ◽  
Experimental Studies ◽  
Leading Edge ◽  
Navier Stokes ◽  
Swept Wing ◽  
High Lift ◽  
Analysis And Design ◽  
Standard Solution ◽  
Function Integration

The use of Fowler flaps and slotted slats in sweptwing aircraft is the standard solution to increase wing lift at take off and landing. In the literature this solution is known as a classical option of high-lift system of commercial subsonic aircraft. The results of numerical and experimental studies of some solutions intended to increase the efficiency of classical high-lift devices are presented. The concept of the trailing-edge devices called "the adaptive flap" is considered as a way to improve flap efficiency. The adaptive concept is characterized by the integration of spoiler downward deflection to the Fowler flap function. Integration of the spoiler with a movable flap provided an increase of lift in the linear region due to flaps deflected to a higher angle. The steeper upwash angle at a leading-edge device may be the reason of an early stall of the main wing. To protect the leading edge a slotted Kruger flap with streamline form has been used. Preliminary design of classical and improved high-lift systems included the determination of aerodynamic shapes and the optimized position for the high-lift devices. Aerodynamic analysis and design were carried out using 2D RANS Navier-Stokes method. A comparison of computed results has shown visible aerodynamic advantages of an improved high-lift system for maximum lift coefficient and refining the behavior of stall characteristics at high angles of attack. The results of wind tunnel tests of aircraft model with adaptive flap showed its effectiveness.

scholarly journals A STUDY OF HIGH LIFT AERODYNAMIC DEVICES ON COMMERCIAL AIRCRAFTS

Aviation ◽  
2020 ◽  
Vol 24 (3) ◽  
pp. 123-136
Author(s):  
Swamy Naidu Venkata Neigapula ◽  
Satya Prasad Maddula ◽  
Vasishta Bhargava Nukala
Keyword(s):  
Lift Coefficient ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Trailing Edge ◽  
High Lift ◽  
Aircraft Wings ◽  
Surface Pressure Distribution ◽  
Trailing Edge Flaps ◽  
Stall Angle ◽  
Kinematic Mechanisms

Aerodynamic performance of aircraft wings vary with flight path conditions and depend on efficiency of high lift systems. In this work, a study on high lift devices and mechanisms that aim to increase maximum lift coefficient and reduce drag on commercial aircraft wings is discussed. Typically, such extensions are provided to main airfoil along span wise direction of wing and can increase lift coefficient by more than 100% during operation. Increasing the no of trailing edge flaps in chord wise direction could result in 100% increment in lift coefficient at a given angle of attack but leading edge slats improve lift by delaying the flow separation near stall angle of attack. Different combinations of trailing edge flaps used by Airbus, Boeing and McDonnel Douglas manufacturers are explained along with kinematic mechanisms to deploy them. The surface pressure distribution for 30P30N airfoil is evaluated using 2D vortex panel method and effects of chord wise boundary layer flow transitions on aerodynamic lift generation is discussed. The results showed better agreements with experiment data for high Reynolds number (9 million) flow conditions near stall angle of attack.

Aerodynamic Investigations of Low-Aspect-Ratio Thin Plate Wings at Low Reynolds Numbers

2012 ◽  
Vol 28 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Y.-C. Liu ◽  
F.-B. Hsiao
Keyword(s):  
Aspect Ratio ◽  
Thin Plate ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Aerodynamic Characteristics ◽  
Flow Structures ◽  
Low Aspect Ratio ◽  
Aerodynamic Properties ◽  
Stall Angle

ABSTRACTTo realize the relationship between flow structures of wingtip vortices and post stall characteristics of low aspect-ratio wings, this paper experimentally studies the aerodynamic characteristics and the corresponding flow structures of the rectangular thin-plate wings at Reynolds numbers between 104 and 105. The aerodynamic properties to be studied include lift, drag, slopes at linear and nonlinear range of the lift curves and lift-to-drag ratios of the tested wings with the aspect ratio varying from 1.0 to 3.0. The flow structures regarding the leading-edge separation vortices and wingtip vortices at upper surface and near-wake regions of the wings are also investigated by smoke-wire visualization. Results indicate that the high stall angle of attack and vortex lift are clearly manifested to induce the nonlinear increase in the lift curves as the aspect ratio reaches less than 1.6. This phenomenon is specifically observed to augment the aerodynamic properties with the decrease of the aspect ratio. Additionally, the corresponding flow visualization also indicates that the wingtip vortices and the areas of highly affected regions are duly increased with the increase of the angle of attack up to 40°, which makes certain that the extra increase of the nonlinear lift results from these vortices. This result can be practically applied to the planform design for unmanned aerial vehicles.

Experimental investigation of the effect of active flow control on the wake of a wind turbine blade

2021 ◽  
pp. 095440622110089
Author(s):  
GholamHossein Maleki ◽  
Ali Reza Davari ◽  
Mohammad Reza Soltani
Keyword(s):  
Experimental Investigation ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Active Flow Control ◽  
Leading Edge ◽  
Wind Turbine Blade ◽  
Plasma Actuators ◽  
Plasma Actuation ◽  
Surface Pressure Distribution ◽  
Stall Angle

An extensive experimental investigation was conducted to study the effects of Dielectric Barrier Discharge (DBD), on the flow field of an airfoil at low Reynolds number. The DBD was mounted near the leading edge of a section of a wind turbine blade. It is believed that DBD can postpone the separation point on the airfoil by injecting momentum to the flow. The effects of steady actuations on the velocity profiles in the wake region have been investigated. The tests were performed at α = 4 to 36 degrees i.e. from low to deep stall angles of attack regions. Both surface pressure distribution and wake profile show remarkable improvement at high angles of attack, beyond the static stall angle of the airfoil when the plasma actuation was implemented. The drag calculated from the wake momentum deficit has further shown the favorable role of the plasma actuators to control the flow over the airfoil at incidences beyond the static stall angle of attack of this airfoil. The results demonstrated that DBD has been able to postpone the stall onset significantly. It has been observed that the best performance for the plasma actuation for this airfoil is in the deep stall angles of attack range. However, below and near the static stall angles of attack, plasma augmentation was pointed out to have a negligible improvement in the aerodynamic behavior.

scholarly journals Beyond analogy: A model of bioinspiration for creative design

2016 ◽  
Vol 30 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Camila Freitas Salgueiredo ◽  
Armand Hatchuel
Keyword(s):  
Design Process ◽  
Design Theory ◽  
Leading Edge ◽  
Knowledge Bases ◽  
Biologically Inspired ◽  
Concept Knowledge ◽  
Bioinspired Design ◽  
Aerodynamic Properties ◽  
Biologically Inspired Design ◽  
The Impact

AbstractIs biologically inspired design only an analogical transfer from biology to engineering? Actually, nature does not always bring “hands-on” solutions that can be analogically applied in classic engineering. Then, what are the different operations that are involved in the bioinspiration process and what are the conditions allowing this process to produce a bioinspired design? In this paper, we model the whole design process in which bioinspiration is only one element. To build this model, we use a general design theory, concept–knowledge theory, because it allows one to capture analogy as well as all other knowledge changes that lead to the design of a bioinspired solution. We ground this model on well-described examples of biologically inspired designs available in the scientific literature. These examples include Flectofin®, a hingeless flapping mechanism conceived for façade shading, and WhalePower technology, the introduction of bumps on the leading edge of airfoils to improve aerodynamic properties. Our modeling disentangles the analogical aspects of the biologically inspired design process, and highlights the expansions occurring in both knowledge bases, scientific (nonbiological) and biological, as well as the impact of these expansions in the generation of new concepts (concept partitioning). This model also shows that bioinspired design requires a special form of collaboration between engineers and biologists. Contrasting with the classic one-way transfer between biology and engineering that is assumed in the literature, the concept–knowledge framework shows that these collaborations must be “mutually inspirational” because both biological and engineering knowledge expansions are needed to reach a novel solution.

Impact and Damage Localisation of Carbon-Fibre-Reinforced Plastic Plates

PAMM ◽  
2011 ◽  
Vol 11 (1) ◽  
pp. 639-640 ◽  
Author(s):  
Andy Ungethuem ◽  
Rolf Lammering
Keyword(s):  
Carbon Fibre ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic

Analysis of High Velocity Impact on Composite Structures

2014 ◽  
Vol 617 ◽  
pp. 104-109 ◽  
Author(s):  
Milan Žmindák ◽  
Zoran Pelagić ◽  
Maroš Bvoc
Keyword(s):  
Carbon Fibers ◽  
Composite Structures ◽  
Impact Resistance ◽  
Leading Edge ◽  
Layered Composite ◽  
Bird Strike ◽  
Out Of Plane ◽  
The Matrix ◽  
Composite Wing ◽  
Considerable Damage

In the recent years a big focus is subjected to the response of structures subjected to out-of-plane loading such as blasts, impact, etc. not only to homogenous materials, but also to heterogeneous materials, such as composites. Such form of loading can cause considerable damage to the structure. In the case of layered composite materials the damage can have several forms, starting from damage in layers up to delamination and full damage of the construction. This paper describes the investigation of shockwave propagation in composite structures caused by impact loading. The composite consists of carbon fibers in a polymer matrix, in which the fibers are much stiffer then the matrix. Finite element simulations were carried out for a “bird” strike impact on a composite wing leading edge. Results show a good impact resistance and good damping abilities of shockwaves.

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