Flap Device for Airframe Noise Reduction

NASA’s Langley Research Center developed a simple, deployable, flap side edge main element link that reduces airframe noise while still enabling a clean cruise configuration. Termed the FLEXSEL (flexible side edge link), this flexible structural link design makes use of hyperelastic materials to provide a smooth geometric transition of minimal spanwise extent between the flap side edge and the main wing. The comparatively small spanwise dimension of the FLEXSEL enables it to achieve the noise reduction without detriment to, and with possible improvement of, other aerodynamic characteristics.