Tuft Testing & Fuselage Interference

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Re: Tuft Testing & Fuselage Interference

Postby WaiexN143NM » Sat May 06, 2017 12:24 am

Hi all,
Just ordered some 2024 .025 from spruce , 2' X 2' , $18.90 w shipping. Will make some root fairings up similar to mike smiths. Will bring to Rio Linda.

WaiexN143NM
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Re: Tuft Testing & Fuselage Interference

Postby Bryan Cotton » Sat May 06, 2017 10:23 am

Very nice. Did you see any performance gains?
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX reserved
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Re: Tuft Testing & Fuselage Interference

Postby mike.smith » Sat May 06, 2017 11:41 am

Bryan Cotton wrote:Very nice. Did you see any performance gains?


Too early to tell for me. I was just doing tuft testing on video. And I was only testing on one side of the aircraft.
Mike Smith
Sonex N439M
Scratch built, AeroVee, Dual stick, Tail dragger
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Re: Tuft Testing & Fuselage Interference

Postby WaiexN143NM » Mon May 22, 2017 2:10 pm

Hi mike,
Any more testing on the fairings? Ive made a set for my waiex. Approx 24 in long x 10 in tall. Made 2 L & R , out of a 2 x2 .025 sheet from spruce. Showed them to waiex 49 don bowen at rio linda. Test fitted them on his waiex. Look good. A little bigger than your fairings.

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Re: Tuft Testing & Fuselage Interference

Postby mike.smith » Tue May 23, 2017 10:56 pm

I haven't had the weather to to any more tests. If anyone does any tests, remember that the stall buffet could be affected by the fairings. In other words, you may not GET the stall buffet before the break. The rule of unintended consequences. So be careful out there.
Mike Smith
Sonex N439M
Scratch built, AeroVee, Dual stick, Tail dragger
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Re: Tuft Testing & Fuselage Interference

Postby mike.smith » Sun Oct 22, 2017 6:55 pm

It was a busy summer, but I finally got to put fairings on both wing roots today and do some tests. I did not notice a difference in take-off roll. My climb out (Vy) appeared to be better, but I don't think that's quantifiable without more tests with various atmospheric conditions and weights. For me it will be gross weight climbs that will tell the story. More to come, hopefully.

In level flight I started collecting data for level flight at 3,000 rpm at 3K, 4K and 5K. Again I'll need to do some more testing, but my TAS were in the 106-111 kt range depending on altitude. WOT for me is about 3,250 rpm.

I then did some stall testing. I did not notice any differences between with/without the fairings. My nose will try hard to drop at 28-30 kts indicated. I can keep it flying straight ahead with rudder. That's what I see with and without the fairings.

I then did left and right spins. Again I did not notice any differences. I did a couple of loops and several aileron rolls, again with no noticeable differences.

On landing I seemed to have to work a little harder to slow down on final, but that may well have been my imagination. I only made two full-stop landings.

So I don't yet know whether there is a quantifiable difference with the fairings, but I certainly did not notice anything negative in terms of stall buffet or other flight characteristics. The tuft testing I did earlier this year did show the air was considerably smoothed with the fairings, so they probably contribute some improvement to aerodynamics.
Mike Smith
Sonex N439M
Scratch built, AeroVee, Dual stick, Tail dragger
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Re: Tuft Testing & Fuselage Interference

Postby WaiexN143NM » Mon Oct 23, 2017 2:37 pm

Hi mike,
Thanks for the update!

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