2011

Active Flow Effectors for Noise and Separation Control

These variable effectors provide enhanced vehicle and aeroelastic control.

New flow effector technology for separation control and enhanced mixing is based upon shape memory alloy hybrid composite (SMAHC) technology. The technology allows for variable shape control of aircraft structures through actively deformable surfaces. The flow effectors are made by embedding shape memory alloy actuator material in a composite structure. When thermally actuated, the flow effector def1ects into or out of the flow in a prescribed manner to enhance mixing or induce separation for a variety of applications, including aeroacoustic noise reduction, drag reduction, and f1ight control. The active flow effectors were developed for noise reduction as an alternative to fixed-configuration effectors, such as static chevrons, that cannot be optimized for airframe installation effects or variable operating conditions and cannot be retracted for off-design or fail-safe conditions.

Benefits include:

  • Increased vehicle control, overall efficiency, and reduced noise throughout all flight regimes,
  • Reduced flow noise,
  • Reduced drag,
  • Simplicity of design and fabrication,
  • Simplicity of control through direct current stimulation, autonomous response to environmental heating, fast response, and a high degree of geometric stability.

The concept involves embedding prestrained SMA actuators on one side of the chevron neutral axis in order to generate a thermal moment and def1ect the structure out of plane when heated. The force developed in the host structure during def1ection and the aerodynamic load is used for returning the structure to the retracted position. The chevron design is highly scalable and versatile, and easily affords active and/or autonomous (environmental) control.

The technology offers wide-ranging market applications, including aerospace, automotive, and any application that requires flow separation or noise control.

This work was done by Travis L. Turner of Langley Research Center. For further information, contact the Langley Innovative Partnerships Office at (757) 864-8881. LAR-17332-1

White Papers

Oscilloscope Fundamentals Primer
Sponsored by Rohde and Schwarz
Reverse Engineering
Sponsored by Servometer
How Paper-based 3D Printing Works: The Technology and Advantages
Sponsored by Mcor Technologies
All About Aspheric Lenses
Sponsored by edmund optics
How to Avoid Bearing Corrosion
Sponsored by Kaydon
SpaceClaim in Manufacturing
Sponsored by SpaceClaim

White Papers Sponsored By: