Quote:
Originally Posted by aerohead
I don't have a pictorial to share,but here's some data to think about.
*Kach22i's prop spinner is about Cd 0.30 in a free stream of air.............
So length does matter,aerodynamically.
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Great information.
I posted for the wavy edge treatment, but got more.
For the record, I made the spinner cone as long as I could without infringing on the rudder vanes.
Also making the cone any longer than the duct might not be the best approach, but does pause for consideration.
The frictional skin drag losses from building a longer duct might negate benefits of straighten out the swilling trust flow.
However the added weight of a longer thrust duct and spinner, and weight so aft of the center of gravity are unforgiving realities on a hovercraft.
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Back to side view mirrors; length, weight, and obscuring forward peripheral vision all must be weighed in the designer's mind. Just as other factors concerning the hovercraft tail cone.
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Saw-tooth or wavy edges may become a fashion at some point, just as with golf ball dimples.
We should be careful about what we wish for, right?
