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Otter @lemmy.ca

3d ago

'Flettner Rotor' - xkcd

Source: https://xkcd.com/3119/

xkcd @lemmy.world

xkcd bot @lemmy.world

4d ago

xkcd #3119: Flettner Rotor

10 comments

I had to look this one up, I didn't realize how old the technology was
https://en.wikipedia.org/wiki/Flettner_rotor
A Flettner rotor is a smooth cylinder with disc end plates which is spun along its long axis and, as air passes at right angles across it, the Magnus effect causes an aerodynamic force to be generated in the direction perpendicular to both the long axis and the direction of airflow.[1] The rotor sail is named after the German aviation engineer and inventor Anton Flettner, who started developing the rotor sail in the 1920s.
The Buckau, the Flettner Rotor Ship, photographed in 1924
- if you have two fletner rotors, you can attach two lights and and a giant face statue to it and make people really regret that bottle of rum.
  
  Master Control Program!
- I saw a short documentary about them. They lost attractivity when fuel was cheap
I thought a lot about these things, and apparently, a less elegant way to tackle this problem is decoupling power harvesting and propulsion. Like, put your best suitable power plant on a boat, then conduct power to best propulsion (probably submerged turbine or something)
- https://en.m.wikipedia.org/wiki/Blackbird_(wind-powered_vehicle)
  Can go directly upwind (no tacking required). Can also be applied to boats.
  
  I can't find the original video I wanted. It was by one of these guys (I think) for sure one of the bigger science creators, but then I DID actually find a more topical video, about this exactly!
  This is one by Steve mould:
  https://youtu.be/u5InZ6iknUM
  Which was inspired by the veritasium one:
  https://youtu.be/jyQwgBAaBag
- NS Savannah has entered the chat
This is the principle behind the rotor ships. It really is just a rotating cylinder.
Sailboats already have ROW over motor boats.

10 comments