Bistable Composite Flap for an Airfoil

A study was conducted to address the challenges associated with investigating a bistable composite flap for an airfoil. A full-scale rotor blade section with a span of 2.114 m and a chord of 0.68 m, fitted with a 1 m span flap was wind-tunnel tested up to a speed of 60 m/s with the flap moving between two stable states for various angles of attack. The blade was approximated as a NACA 24016 section with a 20% chord trailing-edge flap to simplify the analysis. The trailing-edge flap was designed to change between its stable geometries between hover and forward flight conditions for aerodynamic performance improvements. The flap was driven by an electromechanical actuator that was mounted inside the blade D-spar at the leading edge. All of the rotor blade structure remote from this bistable flap region was unmodified and assumed to be completely rigid during wind-tunnel testing.

[1]  L. F. Campanile,et al.  Aerodynamic and aeroelastic amplification in adaptive belt-rib airfoils , 2005 .

[2]  Friedrich K. Straub,et al.  Development and whirl tower test of the SMART active flap rotor , 2004, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[3]  Paul M. Weaver,et al.  A concept for the generation of out-of-plane distortion from tailored FRP laminates , 2004 .

[4]  Mac Gaunaa,et al.  Load alleviation through adaptive trailing edge control surfaces: ADAPWING overview , 2007 .

[5]  Dieter Roth,et al.  Trailing Edge Flaps for Active Rotor Control - Aeroelastic Characteristics of the ADASYS Rotor System , 2006 .

[6]  Mac Gaunaa,et al.  Wind tunnel test on wind turbine airfoil with adaptive trailing edge geometry , 2007 .

[7]  Paul M. Weaver,et al.  Bistable prestressed buckled laminates , 2008 .

[8]  Kevin D Potter,et al.  Modelling and Applications of Thermally Induced Multistable Composites with Piecewise Variation of Lay-up in the Planform , 2007 .

[9]  Michel Verhaegen,et al.  On the proof of concept of a ‘Smart’ wind turbine rotor blade for load alleviation , 2008 .

[10]  Brian Sanders,et al.  Aerodynamic Performance of the Smart Wing Control Effectors , 2004 .

[11]  Michael W. Hyer,et al.  The Room-Temperature Shapes of Four-Layer Unsymmetric Cross-Ply Laminates , 1982 .

[12]  Paul M. Weaver,et al.  Concepts for morphing airfoil sections using bi-stable laminated composite structures , 2008 .

[13]  P. Mellor,et al.  A Short-Stroke Permanent Magnet Aerospace Actuator with High Force-to-Mass Ratio , 2006, IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics.

[14]  Kevin D Potter,et al.  Aeroelastic Study of Bistable Composite Airfoils , 2009 .