Aerodynamic characteristics of two-dimensional membrane airfoils were experimentally investigated in a wind tunnel. The effects of the membrane pre-strain and excess length on the unsteady aspects of the fluid-structure interaction were studied. The deformation of the membrane as a function of angle of attack and free-stream velocity was measured using a high-speed camera. These measurements were complemented by the measurements of unsteady velocity field with a high frame-rate Particle Image Velocimetry (PIV) system as well as smoke visualization. Membrane airfoils with excess length exhibit higher vibration modes, earlier roll-up of vortices, and smaller separated flow regions, whereas the membranes with pre-strain generally behave more similarly to a rigid airfoil. Measured frequencies of the membrane vibrations suggest a possible coupling with the wake instabilities at high incidences for all airfoils.
|Number of pages||18|
|Journal||Journal of Fluids and Structures|
|Publication status||Published - Apr 2010|
|Event||47th AIAA Aerospace Sciences Meeting Including The New Horizons Forum and Aerospace Exposition - Orlando, USA United States|
Duration: 5 Jan 2009 → 8 Jan 2009