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Old 08-24-2018, 01:57 PM   #69 (permalink)
kach22i
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Quote:
Originally Posted by freebeard View Post
It's interesting. I presume the blister on the leading edge is to reduce leeward turbulence. But why the step above and below it?

Oh no, Pelican Parts thread, there goes the rest of my afternoon.
Notice as well, a slight twist at the top root.

This rudder is also acting like a vane straightening stator.

I'm assuming the smaller lower section is simply to reduce the stress, a cantilever moment arm is what the rudder actually is.

Remember, the swirling rotation of the water coming off the prop is best met at by right angles. However if they did that it would turn really well in one direction, and not at all in the other direction. This design is a compromise of some sort.

https://www.cambridge.org/core/journ...91B3DCBB77B7FE


http://www.wavefront.co.jp/CAE/PumpL...propeller.html




http://www.hhscott.com/evinrude/choosing_a_prop.htm
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Last edited by kach22i; 08-24-2018 at 02:06 PM..
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