Wind-tunnel investigation at low speeds to determine flow-field characteristics and ground influence on a model with jet-augmented flaps / Raymond D. Vogler and Thomas R. Turner.

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Bibliographic Details
Main Author: Vogler, Raymond D.
Corporate Author: United States. National Advisory Committee for Aeronautics
Other Authors: Turner, Thomas R.
Format: Government Document Book
Language:English
Published: Washington : National Advisory Committee for Aeronautics, [1957]
Series:Technical note (United States. National Advisory Committee for Aeronautics) ; 4116.
Subjects:
Description
Abstract:A wind-tunnel investigation has been made at low speeds to determine the flow-field characteristics and ground influence on an airplane model having an untapered, unswept wing with an aspect ratio of 8.3 equipped with jet-augmented flaps. Jet-augmented-flap deflections of 55 end 85 degrees were investigated with the jet-blowing energies covering a range representative of that of the output of current jet airplanes. The high lift coefficients associated with the jet-augmented flaps were greatly reduced when the wing was in the proximity of the ground. The adverse effects of the ground increased rapidy as the wing approached the ground, as the Jet-deflection angle increased, or as the momentum coefficient increased. Associated with these reductions in lift coefficient were reductions in both drag coefficient and nose-dawn pitching moment coefficient. No ground effect was noted on the model with either a jet-augmented-flap deflection of 55 degrees when the model was mounted higher than 3 chords above the ground or with a jet-augmented-flap deflection of 85 degrees when the model was mounted more than 5 chords above the ground.
High angles of downwash were measured for downstream locations considered of interest for conventional tail locations. The jet-augmented full-span flap produced wing-tip vortices that increased in strength as the jet momentum coefficient increased and resulted in angles of upflow as large as 20 degree at a location 3 chords behind the wing-tip region.
Item Description:"September 1957."
NACA TN Number 4116.
Physical Description:48 pages : illustrations ; 27 cm.
Bibliography:Includes bibliographical references.
Action Note:committed to retain