scholarly journals Exploitation of a Multifunctional Twistable Wing Trailing-Edge for Performance Improvement of a Turboprop 90-Seats Regional Aircraft

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 122 ◽  
Author(s):  
Francesco Rea ◽  
Francesco Amoroso ◽  
Rosario Pecora ◽  
Frederic Moens
Keyword(s):  
Laminar Flow ◽  
High Speed ◽  
Limit Load ◽  
Trailing Edge ◽  
Aircraft Wings ◽  
Actuation System ◽  
Load Carrying ◽  
Aircraft Performance ◽  
Wing Chord ◽  
Natural Laminar Flow

Modern transport aircraft wings have reached near-peak levels of energy-efficiency and there is still margin for further relevant improvements. A promising strategy for improving aircraft efficiency is to change the shape of the aircraft wing in flight in order to maximize its aerodynamic performance under all operative conditions. In the present work, this has been developed in the framework of the Clean Sky 2 (REG-IADP) European research project, where the authors focused on the design of a multifunctional twistable trailing-edge for a Natural Laminar Flow (NLF) wing. A multifunctional wing trailing-edge is used to improve aircraft performance during climb and off-design cruise conditions in response to variations in speed, altitude and other flight parameters. The investigation domain of the novel full-scale device covers 5.15 m along the wing span and the 10% of the local wing chord. Concerning the wing trailing-edge, the preliminary structural and kinematic design process of the actuation system is completely addressed: three rotary brushless motors (placed in root, central and tip sections) are required to activate the inner mechanisms enabling different trailing-edge morphing modes. The structural layout of the thin-walled closed-section composite trailing-edge represents a promising concept, meeting both the conflicting requirements of load-carrying capability and shape adaptivity. Actuation system performances and aeroelastic deformations, considering both operative aerodynamic and limit load conditions, prove the potential of the proposed structural concept to be energy efficient and lightweight for real aircraft implementation. Finally, the performance assessment of the outer natural laminar flow (NLF) wing retrofitted with the multifunctional trailing-edge is performed by high-fidelity aerodynamic analyses. For such an NLF wing, this device can improve airplane aerodynamic efficiency during high speed climb conditions.

Performance Analysis of the Rayleigh Step Bearing under the Coexistence State of Fluid with Laminar Flow and Turbulence

2011 ◽  
Vol 396-398 ◽  
pp. 886-892
Author(s):  
Ying Jia Wang ◽  
Qi Wu Dong ◽  
Hong Guo ◽  
Shao Qi Cen
Keyword(s):  
Laminar Flow ◽  
Pressure Distribution ◽  
High Speed ◽  
Load Capacity ◽  
Continuity Equations ◽  
Load Carrying ◽  
Flow Domain ◽  
Physical Phenomena ◽  
Deep Cavities ◽  
Coexistence State

In the design of tribology pairs, the Rayleigh step bearing is known as a bearing with the highest load capacity amongst all other possible bearing geometries. This paper mainly discusses a new high-speed bearing with shallow and deep cavities on the inner surface of the bearing, and further the physical phenomena in laminar flow and turbulence regimes was revealed. In doing so, the pressure distribution was calculated first using the continuity equations and then performances in the whole flow domain such as pressure distribution, load-carrying capacity, friction force and friction coefficient were calculated. In addition, a set of optimum geometries are shown to provide the highest load capacity for the Rayleigh step bearing under varied Reynolds number. Finally, associated conclusions were drawn by comparison between results under the coexistence state and under the laminar state.

The Development of Very Light Jet with Unconventional Arrangement

2011 ◽  
Vol 110-116 ◽  
pp. 2219-2227
Author(s):  
Siti Zawiah Md Dawal ◽  
Tuan Ya Tmys ◽  
Yusuf Khairi ◽  
Nukman Yusoff ◽  
Ahmad Yazid Aznijar
Keyword(s):  
High Speed ◽  
Operational Flexibility ◽  
High Lift ◽  
Current Trends ◽  
Surface Configuration ◽  
New Concepts ◽  
Aircraft Performance ◽  
Design Requirements ◽  
Natural Laminar Flow ◽  
Light Jet

In order to be economically viable and competitive, the current trends in designing very light jet aircraft have shown that it is essential to improve the aircraft performance and operational flexibility goal, nevertheless have an efficient cost. The application of unconventional configuration has attracted the designer to achieve that goal. This paper discusses the prospective design of unconventional arrangement which will be applied for very light jet aircraft. The existing of a very light jet configurations is reviewed. New concepts of unconventional configuration for this type of aircraft are discussed. The three-surface configuration is then proposed for the design project. The configuration offers stability and unobstructed cabin. With the appropriate design, the additional weight and interference drag due to the extra surface can be reduced. The new design of aircraft configuration and cabin are discussed. High Speed Natural Laminar Flow airfoil is applied to obtain High Lift/Drag Wing design. The weight and aircraft performances are then estimated. The predicted aircraft performance has satisfied the design requirements and objectives. The design process covered by this paper is only concentrate on initial design. The data from this paper can be continuing in future for the next step of design.

scholarly journals Augmented Aircraft Performance with the Use of Morphing Technology for a Turboprop Regional Aircraft Wing

Biomimetics ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 64 ◽  
Author(s):  
Moens
Keyword(s):  
Laminar Flow ◽  
Performance Improvement ◽  
High Performance ◽  
Leading Edge ◽  
Performance Improvements ◽  
Compliant Structure ◽  
Aircraft Performance ◽  
Natural Laminar Flow ◽  
Morphing Technology ◽  
High Performance Level

This article presents some application of the morphing technology for aerodynamic performance improvement of turboprop regional aircraft. It summarizes the results obtained in the framework of the Clean Sky 2 AIRGREEN2 program for the development and application of dedicated morphing devices for take-off and landing, and their uses in off design conditions. The wing of the reference aircraft configuration considers Natural Laminar Flow (NLF) characteristics. A deformable leading edge morphing device (“droop nose”) and a multi-functional segmented flap system have been considered. For the droop nose, the use of the deformable compliant structure was considered, as it allows a “clean” leading edge when not used, which is mandatory to keep natural laminar flow (NLF) properties at cruise. The use of a segmented flap makes it possible to avoid external flap track fairings, which will lead to performance improvement at cruise. An integrated tracking mechanism is used to set the flap at its take-off optimum setting, and, then, morphing is applied in order to obtain a high-performance level for landing. Lastly, some performance improvements can be obtained in climb conditions by using the last segment of the flap system to modify the load distribution on the wing in order to recover some extended laminar flow on the wing upper surface.

Design Concept of a CFRP External Trailing Edge for Ailerons

2013 ◽  
Author(s):  
Burak Gozluklu ◽  
Gulsen Oncul ◽  
Ugur Koseoglu
Keyword(s):  
Composite Structures ◽  
Outer Part ◽  
Cost Effective ◽  
Design Concept ◽  
Lightning Strike ◽  
Trailing Edge ◽  
Aircraft Wings ◽  
Reinforced Plastic ◽  
Load Carrying ◽  
Edge Side

The most recent civil aircraft dominantly use composite structures such as in the ailerons. However, airworthiness authorities raise concerns about lightning strike damage and repairability if the aileron is made of composite material. Today, aerodynamic profiles of aircraft wings become more complex and challenging for designers who need adequate space to fit conventional “torque box” designs inside the wing surfaces. The aero-surfaces may become too shallow and curved in the trailing edge side of the wing which is highly exposed to edge impact and lightning strike damages. This paper presents a new design concept for Carbon Fiber Reinforced Plastic (CFRP) External Trailing Edge (CETE) structure for the trailing edge of the ailerons. CETE is attached to the main aileron torque box where the main load carrying composite spar, ribs and panels are located. The design objective of the CETE combines various important features such as better strength characteristics against lightning strike and edge impact, and easier repairability with a lighter aileron. This paper also discusses recurring and non-recurring costs and monetary benefits of the new design concept. The CETE concept is as simple as creating a secondary torque box on the trailing edge side of the aileron with two C-section parts; inner and outer parts of CETE. The inner part of CETE provides a secondary spar to the aileron to sustain the main torque box force flows and support the trailing edge panels. The main structural feature of CETE is to form a low loaded zone by its outer part which is located at the outermost region of the trailing edge where mechanical edge impact and lightning strike damages are frequently encountered. It is revealed during the lightning strike tests that, the resulting damages can be catastrophic and located at the trailing edge line where the metallic strips are located. In case of lightning strike damage on the CETE, the aileron is able to carry loads since the flows in the main torque box is minimally disturbed as the inner part of CETE is still intact while the outer part is damaged. Similarly, the damage after edge impact is trapped at the outer section of the CETE where the loads are minimized by CETE design. In case of a larger damage, CETE can be replaced easily instead of replacing the whole aileron which is cost effective in long term although the initial costs seem higher than the conventional designs.

scholarly journals Allometry of wing twist and camber in a flower chafer during free flight: How do wing deformations scale with body size?

2017 ◽  
Vol 4 (10) ◽  
pp. 171152 ◽  
Author(s):  
Yonatan Meresman ◽  
Gal Ribak
Keyword(s):  
Body Size ◽  
Body Mass ◽  
High Speed ◽  
Free Flight ◽  
Trailing Edge ◽  
Adult Body Mass ◽  
Insect Wings ◽  
Wing Chord ◽  
Instantaneous Deformation ◽  
Wing Structure

Intraspecific variation in adult body mass can be particularly high in some insect species, mandating adjustment of the wing's structural properties to support the weight of the larger body mass in air. Insect wings elastically deform during flapping, dynamically changing the twist and camber of the relatively thin and flat aerofoil. We examined how wing deformations during free flight scale with body mass within a species of rose chafers (Coleoptera: Protaetia cuprea ) in which individuals varied more than threefold in body mass (0.38–1.29 g). Beetles taking off voluntarily were filmed using three high-speed cameras and the instantaneous deformation of their wings during the flapping cycle was analysed. Flapping frequency decreased in larger beetles but, otherwise, flapping kinematics remained similar in both small and large beetles. Deflection of the wing chord-wise varied along the span, with average deflections at the proximal trailing edge higher by 0.2 and 0.197 wing lengths compared to the distal trailing edge in the downstroke and the upstroke, respectively. These deflections scaled with wing chord to the power of 1.0, implying a constant twist and camber despite the variations in wing and body size. This suggests that the allometric growth in wing size includes adjustment of the flexural stiffness of the wing structure to preserve wing twist and camber during flapping.

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