Rotor Wake / Wing / Flap Interaction

National Rotorcraft Center / Rotorcraft Center of Excellence

Rotor tip vortices force unsteady flow separation on a stabilator. GTEAG,
1992.
Interactions between complex, vortex-dominated flows, occurring during
transient maneuvers of rotorcraft, can still hold nasty surprises. One
such is the occurrence of three-dimensional unsteady flow separation when
a rotor wake blows down on a lifting wing surface. Having discovered this,
we have turned it into a periodic experiment to study the basic phenomena
including relative time scales and processes of flow separation and reattachment.
Laser sheet images, surface tuft videos, time-averaged and time-resolved
surface pressures, and the three components of the phase-resolved (1-degree
resolution) velocity field have been obtained.
Animated-GIF Visualization of Vorticity Contours
and Velocity Vectors of the Periodic Flow Between a 2-Bladed Rotor and
a Full-SpanWing: Data from Laser Velocimetry.

Related Publications:
Foley, S. M., et al., "A Multi-Diagnostic Approach to Testing V/STOL Craft".
AIAA Paper 92-4008, July 1992.
Funk, R.B., et al., "Vortex-Induced Separation on Lifting Surfaces".
Proceedings of the 3rd ARO Workshop on Rotorcraft Interactional Aerodynamics,
Atlanta, GA. GITAER 94-5, March 1994.
Foley, S.M., et al., "Rotor Wake -Induced Flow Separation on a Lifting
Surface" Journal of the American Helicopter Society, Vol. 40, No.2,
April 1995, p. 24 - 27.
Funk, R.B., et al., "Rotor Wake Interaction with a Lifting Surface".
Proceedings of the American Helicopter Society Annual Forum, Ft. Worth,
TX, May 1995.
Funk, Robert B., PhD. Thesis, School of Aerospace Engineering, Georgia
Institute of Technology, June 1995.