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A comment on Toroidal propeller allows a drone to operate more quietly [pdf]. Parent comment

Re:Toroidal propeller allows a drone to operate more quietly... by throw_away_8080 on Sunday January 29, 2023 @09:38PM (#34575231)
I love when primality is useful. Like cicadas. But 9 is not prime.
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Re:Toroidal propeller allows a drone to operate more quietly... by mLuby on Sunday January 29, 2023 @10:45PM (#34575547)
Whoops I meant to write 11, not 9. I haven't actually heard of an 11-bladed screw, though here's a picture of an 11-bladed pumpjet. https://youtu.be/ugSEIiTZ1Pg?t=386
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Re:Toroidal propeller allows a drone to operate more quietly... by wruza on Monday January 30, 2023 @03:15AM (#34577142)
In wartime it is, and also equals to pi squared.
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