Record Details

Record 1 of 1
Downwash and Wake Behind Plain and Flapped Airfoils
NTRS Full-Text: Click to View  [PDF Size: 27.0 MB]
Author and Affiliation: Silverstein, Abe
Katzoff, S
Bullivant, W Kenneth
Abstract: Extensive experimental measurements have been made of the downwash angles and the wake characteristics behind airfoils with and without flaps and the data have been analyzed and correlated with the theory. A detailed study was made of the errors involved in applying lifting-line theory, such as the effects of a finite wing chord, the rolling-up of the trailing vortex sheet, and the wake. The downwash angles, as computed from the theoretical span load distribution by means of the Biot-Savart equation, were found to be in satisfactory agreement with the experimental results. The rolling-up of the trailing vortex sheet may be neglected, but the vertical displacement of the vortex sheet requires consideration. By the use of a theoretical treatment indicated by Prandtl, it has been possible to generalize the available experimental results so the predictions can be made of the important wake parameters in terms of the distance behind the airfoil trailing edge and the profile-drag coefficient. The method of application of the theory to design and the satisfactory agreement between predicted and experimental results when applied to an airplane are demonstrated.
Publication Date: Jan 01, 1939
Document ID:
19930091726
(Acquired Sep 01, 1996)
Accession Number: 93R21016
Report/Patent Number: NACA-TR-651
Publisher Information: United States
Organization Source: National Advisory Committee for Aeronautics. Langley Aeronautical Lab.; Langley Field, VA, United States
Description: 36p; In English
Relation Information: NACA Technical Report 651.
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: AIRFOILS; WING FLAPS; DOWNWASH; ANGLES (GEOMETRY); WAKES; PREDICTION ANALYSIS TECHNIQUES; WIND TUNNEL TESTS; MONOPLANES; AIR FLOW; TRAILING EDGES; VORTEX SHEETS; WING SPAN; LOAD DISTRIBUTION (FORCES); AERODYNAMIC DRAG; DRAG COEFFICIENTS; THEORIES; EXPERIMENTATION; COMPARISON
Miscellaneous Notes: Also bound with NACA Annual Report 25, p. 179-206.
› Back to Top
Facebook icon, External Link to NASA STI page on Facebook Twitter icon, External Link to NASA STI on Twitter YouTube icon, External Link to NASA STI Channel on YouTube RSS icon, External Link to New NASA STI RSS Feed
Find Similar Records
 
NASA Logo, External Link

NASA Official: Gerald Steeman
Sponsored By: NASA Scientific and Technical Information Program
Site Curator: STI Support Services
Last Modified: July 17, 2014

Privacy Policy & Important Notices Disclaimers, Copyright, Terms of Use Freedom of Information Act USA.gov NASA.gov NASA OCIO Free Adobe PDF Reader Free MS Word Viewer