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Experimental Flight Validation of the Prandtl 1933 Bell SpanloadThis report describes the validation of the 1933 Prandtl bell spanload. This spanload is the minimum induced drag of a wing for a given structural weight with properties that eliminate adverse yaw. Aircraft using the Prandtl bell spanload were flown and investigated. The results of this research show that many previously held assumptions should be rethought, and the creation of aircraft using the Prandtl bell spanload will require considerable new techniques.
Part of this work centered on the use of inverse methods. The usual first-step approach to a computational fluids problem is to create a geometry of the aircraft. Once this geometry exists, the computational fluids solution has been solved; however, the problem of creating the geometry still exists. A very small segment of the computational fluids world has concentrated on inverse solutions. This design approach begins with an end result - the computational fluids solution; from this end result, the geometry is sought.
A more generic inverse tool was desired that would allow for the design of wings - specifically Prandtl bell spanload wings. Such a tool has been developed and allows for variable taper, aspect ratio, sweep, airfoils, and design-lift coefficients; output from the tool results in twist distribution of wings.
Document ID
20210014683
Document Type
Technical Memorandum (TM)
Authors
Albion H. Bowers (Armstrong Flight Research Center Rosamond, California, United States)
Oscar J. Murillo (Armstrong Flight Research Center Rosamond, California, United States)
David E. Berger (Armstrong Flight Research Center Rosamond, California, United States)
Victoria S. Hawkins (Armstrong Flight Research Center Rosamond, California, United States)
Loren J. Newton (Armstrong Flight Research Center Rosamond, California, United States)
Abbigail G. Waddell (Armstrong Flight Research Center Rosamond, California, United States)
Emily D. Glover (Armstrong Flight Research Center Rosamond, California, United States)
Jesse C. Brady (Armstrong Flight Research Center Rosamond, California, United States)
John K. Bodylski (Armstrong Flight Research Center Rosamond, California, United States)
Robert "Red" Jensen (Jacobs (United States) Dallas, Texas, United States)
Rebecca A. Bowers (Jacobs (United States) Dallas, Texas, United States)
Christian Gelzer (Logical Innovations, Inc.)
Deborah J Jackson (Universities Space Research Association Columbia, Maryland, United States)
Rachel J. Suitor (Universities Space Research Association Columbia, Maryland, United States)
Date Acquired
April 27, 2021
Publication Date
July 29, 2021
Subject Category
Aircraft Design, Testing and Performance
Funding Number(s)
WBS: 981698
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
External Peer Committee

Available Downloads

NameType H3284FINAL.pdf STI