Shape Adaptive Airfoil Actuated by a Shape Memory Alloy and its Aerodynamic Characteristics

A three-dimensional adaptive shock control bump made of shape memory alloy is proposed for transonic wings. The methodology to adaptively change the configuration of the airfoil using the shape memory alloy bump to reduce the shock strength and wave drag is numerically demonstrated using an airfoil RAE2822. The shape memory alloy bump is trained to have a flat initial shape with certain initial strain and can swell up when thermally activated. Boyd–Lagoudas phenomenological model is implemented in finite element method and used to compute the two-dimensional profile and the height of the shape memory alloy bump during thermal activation. The results show that the shape memory alloy bump can generate a considerable deflection due to the reverse phase transformation when thermally activated. The dependence of aerodynamic characteristics of the wing on the height of the shape memory alloy bump and the angle of attack is investigated using computational fluid dynamics method. The results show that there is an optimal bump height for a given angle of attack and the bump with a given height is effective only in certain range of angle of attack. Optimization of bump height and the corresponding driving temperature are carried out under variable angles of attack with the lift-to-drag ratio as the objective function.

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Overview of Boeing’s Shape Memory Alloy Based Morphing Aerostructures

Smart Materials, Adaptive Structures and Intelligent Systems, Volume 1 ◽

10.1115/smasis2008-648 ◽

2008 ◽

Cited By ~ 5

Author(s):

F. T. Calkins ◽

J. H. Mabe ◽

R. T. Ruggeri

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Rotor Blade ◽

Continuous Optimization ◽

Engine Performance ◽

Flight Test ◽

Aerodynamic Characteristics ◽

System Level ◽

Variable Geometry ◽

Boeing Company

The Boeing Company has a goal of creating aircraft that are capable of continuous optimization for all flight conditions. Toward this goal we have developed morphing-capable, adaptive structures based on Shape Memory Alloy (SMA) technology that enable component and system level optimization at multiple flight conditions. The SAMPSON Smart Inlet program showed that fully integrated SMA wire bundles could provide a fighter aircraft with a Variable Engine Inlet capability. The Reconfigurable Rotor Blade program demonstrated the ability of highly robust, controlled 55-Nitinol tube actuators to twist a rotor blade in a spin stand test to optimize aerodynamic characteristics. The Variable Geometry Chevrons program, which was the first use of 60-Nitinol for a major aerospace application, included a flight test and static engine test of GE90–115B engine fitted with controlled morphing chevrons that reduced noise and increased engine efficiency. The Deployable Rotor Tab employed tube actuators to deploy and retract small fences which are capable of significantly reducing blade vortex interaction generated noise on a rotorcraft. Most recently, the Variable Geometry Fan Nozzle program has built on the VGC technology to demonstrate improved jet engine performance. The Boeing Company continues to mature SMA technology in order to develop innovative applications and support their commercialization.

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Effects of Trailing Edge Deflections Driven by Shape Memory Alloy Actuators on the Transonic Aerodynamic Characteristics of a Super Critical Airfoil

Actuators ◽

10.3390/act10070160 ◽

2021 ◽

Vol 10 (7) ◽

pp. 160

Author(s):

Binbin Lv ◽

Yuanjing Wang ◽

Pengxuan Lei

Keyword(s):

Mach Number ◽

Shape Memory Alloy ◽

Shape Memory ◽

Angle Of Attack ◽

Aerodynamic Characteristics ◽

Smart Structure ◽

Trailing Edge ◽

Edge Based ◽

Constant Deformation ◽

Transonic Wind Tunnel

A smart structure to actuate a morphing trailing edge based on the super critical airfoil NASA sc-0714(2) was designed and verified in a transonic wind tunnel. The pressure distribution over the wing was measured to evaluate the structure ability and effects of trailing edge deflections on the aerodynamic characteristics. In the experiment, Mach number was from 0.4 to 0.8, and the angle of attack was from 0° to 6°. The results showed that the smart structure based on shape memory alloy could carry aerodynamic loads under transonic flow and deflect the trailing edge. When the driving force was constant, deformation would be influenced by the Mach number and angle of attack. Increasing the Mach number weakened the actuation capability of the smart structure, which decreased the deflection angle and rate of the trailing edge. The influence of the angle of attack is more complex, and couples with the influence of the Mach number. The higher the Mach number, the stronger the influence of the angles of attack. Additionally, the trailing edge deflection would dramatically change the flow structure over the airfoil, such as the shock wave position and strength. If separation was caused by the trailing edge deflection, the limitation of the smart structure would be further found.

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Development of a morphing flap using shape memory alloy actuators: the aerodynamic characteristics of a morphing flap

Smart Materials and Structures ◽

10.1088/0964-1726/23/7/074015 ◽

2014 ◽

Vol 23 (7) ◽

pp. 074015 ◽

Cited By ~ 7

Author(s):

Seung-Hee Ko ◽

Jae-Sung Bae ◽

Jin-Ho Rho

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Aerodynamic Characteristics

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Shape Memory Alloy Based Morphing Aerostructures

Journal of Mechanical Design ◽

10.1115/1.4001119 ◽

2010 ◽

Vol 132 (11) ◽

Cited By ~ 71

Author(s):

Frederick T. Calkins ◽

James H. Mabe

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Rotor Blade ◽

Large Scale ◽

Engine Performance ◽

Flight Test ◽

Aerodynamic Characteristics ◽

System Level ◽

Variable Geometry ◽

Fully Integrated

In order to continue the current rate of improvements in aircraft performance, aircraft and components which are continuously optimized for all flight conditions, will be needed. Toward this goal morphing-capable, adaptive structures based on shape memory alloy (SMA) technology that enable component and system-level optimization at multiple flight conditions are being developed. This paper reviews five large-scale SMA based technology programs initiated by The Boeing Company. The SAMPSON smart inlet program showed that fully integrated SMA wire bundles could provide a fighter aircraft with a variable engine inlet capability. The reconfigurable rotor blade program demonstrated the ability of highly robust, controlled 55-Nitinol tube actuators to twist a rotor blade in a spin stand test to optimize rotor aerodynamic characteristics. The variable geometry chevron (VGC) program, which was the first use of 60-Nitinol for a major aerospace application, included a flight test and static engine test of the GE90-115B engine fitted with controlled morphing chevrons that reduced noise and increased engine efficiency. The deployable rotor tab employed tube actuators to deploy and retract small fences capable of significantly reducing blade-vortex interaction generated noise on a rotorcraft. Most recently, the variable geometry fan nozzle program has built on the VGC technology to demonstrate improved jet engine performance. Continued maturation of SMA technology is needed in order to develop innovative applications and support their commercialization.

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