An Experimental Investigation of Trailing Vortices Behind a Wing with a Vortex Dissipator
An experimental study was carried out on a rectangular wing in the NASA-Ames 7- by 10-Foot Wind Tunnel. Flow visualization studies were made using a tuft grid and smoke. Preliminary studies showed that the introduction of a bluff body into the trailing vortex downstream of the wing resulted in modification of the vortex. Further studies showed that a small vertical panel, termed a vortex dissipater, mounted on the wing upper surface near the wing tip also caused modification of the vortex. Both the smoke and tuft grid visualization studies indicated that the dissipater caused a significant reduction in the maximum tangential velocities in the trailing vortex. Additional studies using a hot wire anemometer showed significant reductions in the magnitude of the tangential velocities, increases in the cross-sectional dimensions of the core of the dissipated vortex and changes in the turbulence structure. Limited flight tests with a dissipater fitted to a Convair 990 wing tip and using a Lear jet aircraft as a probe indicated that the rolling acceleration and the degree of roll control required was less in the modified vortex than in the unmodified vortex.
KeywordsVortex Core Bluff Body Vortex Center Flight Test Vortex Breakdown
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- 1.Andrews, W. H.: Flight Evaluation of the Wing Vortex Wake Generated by Large Jet Transports. Symposium on Aircraft Wake Turbulence, Seattle, September, 1970.Google Scholar
- 2.McGowen, W. A.: Trailing Vortex Hazard. Society of Automotive Engineers Business Aircraft Meeting, Wichita, Kansas, April, 1968, Paper G80220.Google Scholar
- 4.Drinkwater, F.: Flight Operations, NASA-Ames Research Center, Moffett Field, Calif., Flight Test Reports.Google Scholar
- 5.Crow, S. C., and Murman, E. M.: Trailing-Vortex Experiments at Moses Lake, Boeing Scientific Research Laboratories Technical Communication 009, February, 1970.Google Scholar
- 6.Lambourne, N. C., and Bryer, D. W.: The Bursting of Leading Edge Vortices. Brit. Aeronautical Research Council R and M No. 3282, 1962.Google Scholar
- 7.Bisgood, P. L., Maltby, R. L., and Dee, F. W.: Some Work on the Behaviour of Vortex Wakes at the Royal Aircraft Establishment. Symposium on Aircraft Wake Turbulence, Seattle, September, 1970.Google Scholar