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Flap-Edge Blowing ExperimentsThis Appendix documents the salient results from an effort to mitigate the so-called flap-edge noise generated at the split between a flap edge that is deployed and the undeployed flap. Utilizing a Coanda surface installed at the flap edge, steady blowing was used in an attempt to diminish the vortex strength resulting from the uneven lift distribution. The strength of this lifting vortex was augmented by steady blowing over the deployed flap. The test article for this study was the same 2D airfoil used in the steady blowing program reported earlier (also used in pulsed blowing tests, see Appendix G), however its trailing edge geometry was modified. An exact duplicate of the airfoil shape was made out of fiberglass with no flap, and in the clean configuration. It was attached to the existing airfoil to make an airfoil that has half of its flap deployed and half un-deployed. Figure 1 shows a schematic of the planform showing the two areas where steady blowing was introduced. The flap-edge blowing or the auxiliary blowing was in the direction normal to the freestream velocity vector. Slot heights for the blowing chambers were on the order of 0.0 14 inches.
Document ID
20030065820
Acquisition Source
Langley Research Center
Document Type
Other
Authors
Gaeta, R. J.
(Georgia Tech Research Inst. Atlanta, GA, United States)
Englar, R. J.
(Georgia Tech Research Inst. Atlanta, GA, United States)
Ahuja, K. K.
(Georgia Tech Research Inst. Atlanta, GA, United States)
Date Acquired
August 21, 2013
Publication Date
May 31, 2003
Publication Information
Publication: Application of Circulation Control Technology to Airframe Noise Reduction
Subject Category
Aerodynamics
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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