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Question
Hello Paul,
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I am trying to make a windmill. Please look at my sketch. Can you think of an answer to my two questions please?
Many thanks.
Mike
Mike
I don't know of any material that will pass air one direction and block it the other, but that process can be done mechanically. Like any check valve, you can design any number of systems that open and close depending on fluid flow direction. Consider an array of louvers like venetian blinds that each rotate on a hinge. In one direction they fly open, in the other they swing shut. Without doing an analysis, I doubt that would be more efficient than a conventional windmill because you would be relying on drag of the closed panel whereas the lift from an airfoil can be much stronger than drag. On the other hand, your system would be very reliable and unlikely to overspin in high winds.
That reminds me of another type of simple windmill that has cups mounted horizontally such that in one direction the drag is small, in the other the drag is large. Rotation is very simple and reliable if the wind is high enough to overcome static friction of the system.
Paul
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Aeronautical Engineering
Answers by Expert:
Paul Soderman
Expertise
Aeronautics, Fluid Mechanics, Aeroacoustics, Noise Control, Muffler Design, Wind Tunnel Research.... I know nothing about India - do not ask about schools, jobs, application requirements, career choices, etc. for India. Please, no text message verbiage; I prefer full words in full sentences. Thanks.
Experience
38 years as research engineer at NASA
Publications
AIAA, NASA
Education/Credentials
B.S. and M.S. Aeronautical Engineering - U. of Washington
Graduate work Standford U.
Awards and Honors
AIAA Associate Fellow (American Institute of Aeronautics and Astronautics)
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