Thread: Duct Duct Go
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Old 03-24-2021, 11:23 AM   #26 (permalink)
aerohead
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Quiet

Quote:
Originally Posted by freebeard View Post
No further progress on this, but I did find this video:



It's all speculative CGI, but it's an interesting concept. For instance it claims 15x thrust, where Jetoptera gets to that with an additional box wing. 10x from Coanda and one level of entrainment?

edit: On the subject of quadcoptera, I've been learning about the Prandtl wing and found a mention of a Prandtl propeller! It would be longer ...but quiet. All the noise comes from the tips.
Check out the Vietnam War-era, Lockheed YO-3 'Quiet Star,' battlefield observation plane and its unique, hand-carved propeller. Large diameter, low rpm. Pima Air Museum, near Tucson, Arizona,has a restored example in their collection.
And 'Q-tip' propellers.
Virginia-Class nuclear submarine propulsor ( if you have TOP SECRET clearance )
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