Supersonic Testing of Natural Laminar Flow on Sharp Leading Edge Airfoils. Recent Experiments by Aerion Corporation

2012 ◽  
Author(s):  
Andres Garzon ◽  
Jason Matisheck
Keyword(s):  
Laminar Flow ◽  
Leading Edge ◽  
Natural Laminar Flow ◽  
Sharp Leading Edge

High-Lift Simulations of Slotted, Natural-Laminar-Flow Airfoils with Drooped Leading Edge

2020 ◽  
Author(s):  
Hector D. Ortiz-Melendez ◽  
Ethan Long ◽  
George Toth ◽  
Kathryn Keely ◽  
James G. Coder
Keyword(s):  
Laminar Flow ◽  
Leading Edge ◽  
High Lift ◽  
Natural Laminar Flow

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.

scholarly journals Aerodynamic Shape Design and Validation of an Advanced High-Lift Device for a Regional Aircraft with Morphing Droop Nose

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Alessandro De Gaspari ◽  
Frédéric Moens
Keyword(s):  
Laminar Flow ◽  
Tracking System ◽  
Three Dimensional ◽  
Design Procedure ◽  
Leading Edge ◽  
Optimization Procedure ◽  
Shape Design ◽  
High Lift ◽  
Aerodynamic Shape ◽  
Natural Laminar Flow

In the present work, the aerodynamic shape design of an advanced high-lift system for a natural laminar flow (NLF) wing, based on the combination of a morphing droop nose and a single slot trailing edge flap, is presented. The paper presents both the aerodynamic design and optimization of the NLF wing and the high-lift configuration considering the mutual effects of both flap devices. Concerning the morphing droop nose (DN), after defining the parameterization techniques adopted to describe the geometry in terms of morphing shape and flap settings, the external configuration is obtained by an aerodynamic shape optimization procedure able to meet geometrical constraints and the skin structural requirements due to the morphing. The final performance assessment of the three-dimensional high-lift configurations is performed by high-fidelity aerodynamic analyses. The design procedure is applied to a twin-prop regional aircraft equipped with a natural laminar flow wing. The morphing droop nose is compatible with an NLF wing that requires the continuity of the skin and, at the same time, extends the possibilities to improve the performances of the class of regional aircraft which usually are not equipped with conventional leading edge devices. Additionally, the morphing technology applied to the flap allows the design of a tracking system fully integrated inside the airfoil geometry, leading to a solution without external fairings and so with no extra friction drag penalty for the aircraft.

Keel Design for Low Viscous Drag

1987 ◽  
Author(s):  
Clifford J. Obara ◽  
C. P. van Dam
Keyword(s):  
Boundary Layer ◽  
Laminar Flow ◽  
Laminar Boundary Layer ◽  
Leading Edge ◽  
Boundary Layer Transition ◽  
Viscous Drag ◽  
Hydrodynamic Characteristics ◽  
Sweep Angle ◽  
Layer Transition ◽  
Layer Flow

In this paper, foil and planform parameters which govern the level of viscous drag produced by the keel of a sailing yacht are discussed. It is shown that the application of laminar boundary-Layer flow offers great potential for increased boat speed resulting from the reduction in viscous drag. Three foil shapes have been designed and it is shown that their hydro­dynamic characteristics are very much dependent on location and mode of boundary-Layer transition. The planform parameter which strongly affects the capabilities of the keel to achieve laminar flow is lea ding-edge sweep angle. The two significant phenomena related to keel sweep angle which can cause premature transition of the laminar boundary layer are crossflow instability and turbulent contamination of the leading-edge attachment line. These flow phenomena and methods to control them are discussed in detail. The remaining factors that affect the maintainability of laminar flow include surface roughness, surface waviness, and freestream turbulence. Recommended limits for these factors are given to insure achievability of laminar flow on the keel. In addition, the application of a simple trailing-edge flap to improve the hydrodynamic characteristics of a foil at moderate-to-high leeway angles is studied.

Application Of Elastic Layers To Register Pressure Field On The Model Surface In Supersonic Flow

2016 ◽  
Vol 11 (1) ◽  
pp. 23-33
Author(s):  
Maxim Golubev ◽  
Andrey Shmakov
Keyword(s):  
Surface Waves ◽  
High Frequency ◽  
High Speed ◽  
Pressure Pulsation ◽  
Pressure Field ◽  
Leading Edge ◽  
Supersonic Wind Tunnel ◽  
Register Pressure ◽  
Elastic Layers ◽  
Sharp Leading Edge

The work presents the results of application of panoramic interferential technique which is based on elastic layers (sensors) usage to obtain pressure distribution on the flat plate having sharp leading edge. Experiments were done in supersonic wind tunnel at Mach number M = 4. Sensitivity and response time are shown to be enough to register pressure pulsation against standing and traveling sensor surface waves. Applying high-frequency image acquiring is demonstrated to make possible to distinguish at visualization images high-speed disturbances propagating in the boundary layer from low-speed surface waves

Dynamic Stall over a Pitching Natural-Laminar-Flow Airfoil

AIAA Journal ◽  
2021 ◽  
pp. 1-12
Author(s):  
Patrick R. Hammer ◽  
Daniel J. Garmann ◽  
Miguel R. Visbal
Keyword(s):  
Laminar Flow ◽  
Dynamic Stall ◽  
Natural Laminar Flow
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