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NASA's PRANDTL-D Flying Wing - No Vertical Surfaces With No Control Problems

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Albion H. Bowers - Chief Scientist at the NASA Armstrong Flight Research Center
https://www.nasa.gov/centers/armstrong/about/biographies/management/bowers.html
He discovered that some of the fundamental assumptions made about the best way to design a wing are wrong. He’s been doing flight testing on model aircraft made by his summer interns as you’ll see in the videos and articles below.

Please do a video about this, and make a kit or set of plans that I can use to make one myself!

Why The PRANDTL-D Flying Wing is Different
1. Maximizing lift and minimizing drag for a given structure (mass) rather than for a given span length. Using a bell shaped lift distribution instead of elliptical gives more lift and less drag for a specific mass/weight of wing. Better for when span length is not the main design constraint.
2. Creating a bell shaped lift distribution means twisting the wing so that the generated lift at the wing tips is forward instead of straight up (propulsive yaw/thrust). The wing tip vortex is spread over the last section of wing and is used to yaw in a beneficial direction.
3. Since the wing naturally yaws in a beneficial direction no vertical surfaces or drag inducing control surfaces are required. No rudder needed. No control problems. No stall spin problems. Replicates bird flight more closely.
4. The reason that other flying wings still have adverse yaw is a mix of being built with the wrong twist or lift distribution, and that the control surfaces are too far inboard causing additional adverse yaw. Keeping the control surfaces near the wing tips minimizes adverse yaw coming from drag induced by their edges/surfaces.
5. This doesn’t mean that current wing/airplane designs don’t work (they clearly do), it means they aren’t as efficient and elegant as they can be.

Please watch his presentations/videos and read the NASA articles below. He has said that he will be releasing a more detailed paper in the near future.

He has released his research paper including the relevant equations and wing twist distribution.
On Wings of the Minimum Induced Drag Spanload Implications for Aircraft and Birds:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003578.pdf


Here are the slides from his presentation: http://www.twitt.org/Bowers%20Slides.pdf

AMA EXPO Presentations and Interview
AMA EXPO 2014 Presentation: https://www.youtube.com/watch?v=RoT2upDbdUg
AMA EXPO 2016 Presentation: https://www.youtube.com/watch?v=QYlucUIpcbQ
AMA EXPO 2016 Interview: https://www.youtube.com/watch?v=KEDkmYfhzuw
Do you love Model Airplanes? NASA is looking for you!: https://www.youtube.com/watch?v=c2Bq-qcqyHM
Aero-TV: NASA's Prandtl-D Project - Preliminary Research Design to Lower Drag:
https://www.youtube.com/watch?v=0Oh0Q0Dv28I

NASA Articles
http://www.nasa.gov/centers/armstrong/features/Prandtl-D_validating_new_wing_design.html
http://www.nasa.gov/centers/armstrong/news/FactSheets/FS-106-AFRC.html
http://www.nasa.gov/centers/armstrong/features/students_advance_mars_plane_concept.html

NASA Image Gallery of PRANDTL-D
http://www.nasa.gov/centers/armstrong/multimedia/imagegallery/PRANDTL_Wing/index.html

Videos From NASA Armstrong Flight Research Center
PRANDTL-D No. 3 Takes Flight: https://www.youtube.com/watch?v=FC6WSo2grNs
Proving Prandtl- With A Twist!: https://www.youtube.com/watch?v=Hr0I6wBFGpY
NASA Armstrong PRANDTL-D Interns, Summer 2015: https://www.youtube.com/watch?v=ATs8zhuhucw
The Mars Airplane Live Event- Al Bowers on PRANDTL-M: https://www.youtube.com/watch?v=Q3YDxxvrGTw
Real Martians Moment: Flight on Mars: https://www.youtube.com/watch?v=SdJbkZMhWpE

TEDxNASA@SiliconValley - Al Bowers - Toward More Bird-Like Flight: Thinking Outside the Box
https://www.youtube.com/watch?v=223OmaQ9uLY
 
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