Streamline Wire Rods for tail section

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Streamline Wire Rods for tail section

Postby scubarider2 » Sun Oct 24, 2010 7:49 pm

Was wondering if anyone had any experience with removing the tail wire supplied and replacing with the streamline wire rods with terminal ends. You can see a picture of what i am talking about at Steen Aero Lab-Bruntons Flying Wires:
www.steenaero.com/Products/flying_wires.cfm
Was thinking this would eliminate the need to tighten the wires when they stretch. Would also give you better aerodynamics and possible some extra mph.
Any thoughts?
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Re: Streamline Wire Rods for tail section

Postby xpflyr » Sun Oct 24, 2010 11:11 pm

Very interesting.
If I get to that point and I hope I do, I would try them.
Thanks!
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Re: Streamline Wire Rods for tail section

Postby Roger » Mon Oct 25, 2010 1:58 pm

Dennis:
Seems like I remember that way back,(maybe right after the civil war), that Just origonally (sp) had those type flying rods on the horizontal stabs on the Escapade. Maybe ask Troy his thoughts.
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Re: Streamline Wire Rods for tail section

Postby Dave Krall CFII SEL SES » Mon Oct 25, 2010 2:23 pm

There's been previous discussion on this.
I was told a few years ago that the empenage airframe was made to "give a little" under flying loads and that streamline rod is too ridgid for the Highlander tailfeathers, thereby transfering too much load too abruptly to the airframe.

Makes sense to me, so I've never thought the streamline rod "looked" good on a Highlander.
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Re: Streamline Wire Rods for tail section

Postby preacoupe » Tue Oct 26, 2010 2:16 pm

Dennis,

My Escapade (Early one) does have steel rods on the bottom, with wires called for on the top. Advantage? Not sure. I would think the rods would dominate the stresses. I would like the adjustable rods on top to make life easier. BTW the bottom ones are fixed. One other thing I think I heard was that the "flat" rods might have a tendency to vibrate, whereas the round ones probably wouldn't....a resonance thing.

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Re: Streamline Wire Rods for tail section

Postby scubarider2 » Tue Oct 26, 2010 6:56 pm

Thanks guys, you have given me lots to think about. I have seen these on other planes mostly acrobatic ones. So, I figured if they could use them the Just planes could. I heard that the flat ones were the most aerodynamic and would provide less drag. I wrote an email to Just to ask their opinion. Will let you know.
:)
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Re: Streamline Wire Rods for tail section

Postby SheepdogRD » Wed Dec 15, 2010 10:09 pm

Just found an old video that discusses drag. At the end, it talks about wire drag. Pretty interesting . . .

http://www.youtube.com/watch?v=ftq8jTQ8ANE
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Re: Streamline Wire Rods for tail section

Postby Gary H » Thu Dec 16, 2010 12:21 am

Guys,,, just follow the instructions, I'll say it again, JUST FOLLOW THE INSTRUCTIONS!!
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Re: Streamline Wire Rods for tail section

Postby scubarider2 » Thu Dec 16, 2010 8:56 am

Gary, that is why they call it experimental ! :P
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Re: Streamline Wire Rods for tail section

Postby scubarider2 » Thu Dec 16, 2010 9:04 am

Wow, what a cool old video. A must see! :mrgreen:
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Re: Streamline Wire Rods for tail section

Postby Gary H » Sun Dec 19, 2010 8:48 pm

YEP, THAT'S RIGHT SCUBARAIDER, and thats why some highlanders fly better than other highlanders ! :D
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Re: Streamline Wire Rods for tail section

Postby Johnny C! » Mon Dec 20, 2010 9:33 am

Great video...

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Re: Streamline Wire Rods for tail section

Postby flyin-low » Tue Dec 21, 2010 3:19 am

It’s a good video, but the numbers are much exaggerated since they used 210 mph for their test speed. It states the drag of a wire will be 10 times greater than that of an airfoil which has an equal maximum cross section.

Drag increases exponentially with speed and given a modest speed of 85-100 mph the drag of the wire would be closer to 2-4 times that of an airfoil. This assumes that you can get the airfoil perfectly aligned with the air stream at your chosen cruise speed. If you don’t get the airfoil aligned with the air stream, it’s possible that you’ll increase the cross sectional area and end up adding more drag than the original wire had.

A number of years back I saw an Avid Flyer with air foiled aluminum tubes slipped over the wires. The tubes were allowed to spin freely on the wire and had two aluminum washers installed on each end of the tube to prevent it from jamming in any single position. I assume they were allowed to spin to make them self aligning, and since they weren’t rigidly attached it should still allow the tail section to flex. I didn’t have a chance to talk to the owner and ask how well it worked, but it seemed like a reasonable idea.
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Re: Streamline Wire Rods for tail section

Postby danerazz » Tue Dec 21, 2010 2:12 pm

I would be nervous of something like that spinning around freely on the tail wires (or any wires). The chances that they are just fluttering around and chaffing through the wires in short order instead of nicely just streamlining to a stable angle is too great. They would be very light, and unless you damped the ocillations out somehow, I really question whether they would do more harm than good. All this drag reduction is great to talk about, but as stated above, it is an exponential scale. If the Highlander was a high-speed, maximum efficiency design trying to get every knot out of the least amount of horsepower, then all this may be worth the effort. Instead it is a specialized design that is usally (dare I say) overpowered with some kind of climb-ish prop so that it can get off the ground quickly and climb fast. These are two totally different missions requiring totally different attention to details. Just looking at the drag of the airfoil, the wires on the tail are not going to affect much. Now, put a high-speed instead of high-lift wing on it and the wires become important, but you won't be winning any STOL contests with it, and forget about grass-friendly tires.
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Re: Streamline Wire Rods for tail section

Postby flyin-low » Tue Dec 21, 2010 5:28 pm

My apologies, I didn’t describe that very well. When I said the tubes could spin freely, I meant you could spin them with one hand and a firm grip. They didn’t free wheel like a bearing.

It’s hard to describe how much friction there was, but it didn’t feel like enough to stop them from straightening out at 80 mph. This is no guarantee that they won’t flutter at some point, but it would allow you to find the correct incidence after which they could be locked down quite easily. I don’t think I would add them to plane which is already flying, but if the wires are being changed for some reason adding airfoil tubes wouldn’t add much weigh, time or expense to the project and they could easily be cut off if things didn’t work out.

If we all bought the correct vehicle for the intended mission, the only people buying trucks would be farmers and construction workers. The majority of us should be driving Dodge mini vans and Honda Civics. There’s nothing wrong with trying to squeeze a little more speed out of our toys, regardless of what their intended mission was.
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