NASA's Albion H. Bowers - "Why Birds Don't Have Vertical Tails" - AMA EXPO 2014
Why Aviation Stack Exchange recommends it
Aviation Stack Exchange users link it when explaining bird-like wing designs, bell-shaped lift distribution and proverse yaw, citing specific timestamps in the talk.
Recommended by 2 people across 2 different months, 2020 to 2023.
What it is
NASA Dryden researcher Albion (Al) Bowers presents at AMA Expo 2014 on why birds manage without vertical tails. He covers Prandtl's bell-shaped lift distribution, proverse yaw, and what it could mean for efficient wing design. It is a conference talk to a model aviation audience.
What people said
Strong rec Azendale · 2023-09 · Aviation Stack Exchange · on “How do birds coordinate their turns?”
You might take a look at Prandtl wings, and research by Al Bowers. The lift distribution on most bird wings are different than an most planes. This different lift distribution can mean that the tip of the wing is at such an AoA to actually get a "thrust" out of it -- this is actually what you would see with a winglet. (See 17:54 in the below video.) With the right lift distribution, instead of adverse yaw, you can get proverse yaw. Birds can warp their wing to customize the effective angle of attack across the wingspan. This is similar to washout on a plane wing, except a bird can change this dynamically in flight. This can be (is) exploited to adjust the drag on each side to cause yaw witho
Recommends ROTOR · 2020-05 · Aviation Stack Exchange · on “Why isn't the bell distribution used?”
you are wrong.when flying in design- range,wingtips allways produce small lift..listen at 20:58-22:00 [this video]
Cites user53913 · 2021-01 · Aviation Stack Exchange · on “Can Bell-lift distribution increase glider efficiency(L/D)?”
Can a Bell-lift distribution without a rudder has higher overall efficiency (L/D) then current gliders, if the wingspan is not limited? (Is it really possible that most of aerospace engineers don't understand the essence of Al Bowers' PRANDTL project? What is stopping the aero-industry from accepting his "new" design ideas? Is he wrong, or do they not want the risk of an unproven concept?) AL Bowers say at 13:20 that Bell distribution increase L/D ratio by 12.5% ! ?