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I've always wondered about this...
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That is a very enlightening video. I think its the flutter that is induced behind the round shape that makes the drag so high. The Hobby industry sells 1/4 inch streamline AL tubing to put over tail wires to streamlined flying wires.Brooks Cone
Southeast Michigan
Patrol #303, Kit build -
That's a graphic demonstration!
That data roughly suggests that a set of round flying wires is almost the same scale of drag as the whole horizontal tailplane over again.
I imagine the leaf spring must create plenty of drag too...
Certainly makes you think about the penalties of a round tube for the main landing gear strut...Comment
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That's some cool stuff! You sure can't beat that. -
I would have a concern that after a couple years, that PVC would get a little brittle and take a beating if you do any off airport landings. I was thinking of welding some angle iron (or angle aluminum) to the front and back of the shock strut to give it a more aero dynamic shape... maybe the front of the landing gears as well. Over Kill? seems like a pretty easy addition, adds a couple pounds (aluminum would be lighter) - should be good for a Knot or two.
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Stunning! I never would have thought the difference would be that significant. It occurred to the Wright brothers that maybe they should steamline the shape of the struts on their airplanes, but when they tested various shapes in their wind tunnel, they concluded that a rectangular cross section with slightly rounded corners presented no more drag than any other shape, so that's what they used.Comment
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I've seen this information on paper before, but never really grasped how big of a difference there really was between the different profiles. I can see why Bob went to the effort of fairing the back of the Bearhawk series gear legs.Comment
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My memory of Aerodynamics and Physics would say that, if the drag is 9 at 210 mph, then it would be 3 at 105 mph.Brooks Cone
Southeast Michigan
Patrol #303, Kit buildComment
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You only need to remember one equation:
Drag = 1/2 x air density x airspeed^2 x drag coefficient x area.
BUT... In this case you describe, we would need to change the airspeed in both tests, not just one. So both results would reduce by a factor, and the difference between them will be ??? *unknown until you do the test
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