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-   -   what is your take on wing root fairings? (https://vansairforce.net/community/showthread.php?t=94871)

Mike S 01-05-2013 10:35 AM

Terry, I believe this was done to Steve Barnards plane, n157st.

Steve only flew a short time with the root fairings, and then removed them.

At the time, he had the fastest 6a, Tracy Salor had the fastest 6, and of course Dave Anders with his 4 was the fastest RV. This was in the "golden" years of CAFE competition.

Mike S 01-05-2013 10:55 AM

Quote:

Originally Posted by F1Boss (Post 731551)
To better understand the design intentions, read up on the AR-5.

http://www.ar-5.com/tapes.html

"Why it goes so fast" is a really interesting story, his discussions on the nozzle effect are very good.

Falcontech 01-15-2013 08:17 PM

I have been reading Kelly Johnson's autobiography "More Than My Share of It All." He was trying to correct a directional instability problem on the Lockheed model 10 Electra. One of the fixes was "we removed the wing fillets, or fairings onto the fuselage--put on apparently because they were coming into style and being used successfully on such airplanes as the Douglas DC-1."

ronschreck 03-04-2013 12:47 PM

Me too.
 
I would also be interested in something other than the standard rubber fairings. Not trying to go faster (tho that would be OK) but trying to find something that won't break away at the most inopportune times. You wouldn't believe the racket that a flailing rubber fairing makes when it separates at 200+ knots!

I suppose I could lay up some composite fairings but there must be someone who has already done the work. Anybody?

Sid Lambert 03-04-2013 01:58 PM

Quote:

Originally Posted by ronschreck (Post 749658)
You wouldn't believe the racket that a flailing rubber fairing makes when it separates at 200+ knots!


Haha, same thing happened to me. (170kts though). Coming out of a loop one of the rubbers popped out and made a horrible noise. It's amazing how calmly you get the airplane straight, level and slowed down before trouble shooting those noises.

Back to the thread topic....

The Speed with Economy book talks in length about how any angle less than 90 needs to have a radiused fairing. Our wings meet the fuse with less than 90 because of dihedral. I haven't tested but I have heard 20 people say 20 different things.

woodmanrog 03-04-2013 04:27 PM

Get rid of them
 
On my first RV6 I had molded wing root fairings. They looked really nice. My friend(guru) who has won more awards for RV construction and speeds than most, took one look and told me to get rid of them and put it back to Van's design. I did speed test and GAINED 8 KNOTS by going back to the original design.(Read my article on speed mods) I just might mention that gaining speed in the air by reducing drag means a difference in amount of fuel used at a given RPM. I happen to think that is an important benefit to having a slicker airplane. Also I might mention that if the distance between the fairing and the fuselage is the required 1/8 inch, the rubber will not come out at 17 knots. I'll prove that to anybody who wants to go for a ride with me.

JonJay 03-04-2013 05:05 PM

Not too many of us going purposefully over 200kts (Smokey). I would find out what extrusion supplier Van's is using for that part. My guess is that it is a standard product. With the thousands of extrusions out there, if you where able to find one with a deeper cut or overlap and perhaps slightly thicker and/or stiffer, it might just work. That would be a relatively easy "fix".
Another idea, and one I am not a big fan of, would be to glue the extrusion on. This has been tried with mostly bad results. However, if you where to just glue a few inches of each end, perhaps it would keep the thing from un-zipping?

KRviator 03-05-2013 10:57 PM

Quote:

Originally Posted by John Clark
Here is a shot of a 747-400, no radius, no fairing. Cool paint job, though!

That's what happens when you park your airplane too close to the perimeter fence in Sydney, overnight!

chrish 03-05-2013 11:27 PM

Quote:

Originally Posted by KRviator (Post 750308)
That's what happens when you park your airplane too close to the perimeter fence in Sydney, overnight!

The problem we are having is too many of them are being 'parked' permanently with no replacements. In fact the boss has no qualms about parking all of the aircraft for pilots wearing a red tie :mad:

MarkSchmitz 03-06-2013 11:31 AM

Evo style fairings on RV-8
 
Quote:

Originally Posted by F1Boss (Post 731551)
The wing root fairing makes up for an 'incorrect' fuselage section at the wing attach area. I'll wager the 747 has a nearly 90 deg angle there, with no fuselage taper. Very efficient, almost like a mid-wing application.
To exhibit the opposite, look at a Spitfire, or a C-47: absolutely the largest fairings in the business!
All 3 ships are known as good flying types, and very good in their intended mission profiles. The fairings fitted to each help with their success.
A wing root fairing is supposed to help with climb, and maneuvering flight - both higher alpha than cruise flight.
To better understand the design intentions, read up on the AR-5. I see similar straight flow lines on the Evo fuselage, if that is the design intention of the application.
Does the typical RV need a larger fairing? Probably not, but simplicity has triumphed over any R&D to determine if such might help.
Personally, I think they 'look' appropriate, so they are fitted to my designs. Do they help? Dunno, but the chick's dig 'em.:D
Also, on the Evo, part of the flap operating system is hidden under the fairing...so they actually serve a second purpose!
I have sold a few sets of fairings to -8 builders, but have never heard back regarding any performance changes.

Carry on!
Mark


I'd be interested in hearing from anyone actually flying with the Evo style fairings on their RV-8. Very much like the look, just wondering about flight characteristic impact (aside from a possible speed penalty.)

Thanks -

Another Mark...


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