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rwaltman

Joined: 12 Aug 2009
Posts: 5

Posted: Tue Sep 08, 2009 7:55 am Post subject: Vortex Generators

The post "Summary of Kolb database" says 35% of the poll participants use

vortex generators in their machines.



Can somebody provide figures on the their aircraft weight and stall speed

before and after installing the VGs?



I am asking because I am interested in a project, (not a Kolb, sorry,)

that could be flown as a legal Part-103 ultralight if I can bring down the

stall speed.



Thanks,



Roberto Waltman

_________________
Roberto Waltman

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Tue Sep 08, 2009 1:42 pm Post subject: Re: Vortex Generators

 	  rwaltman wrote: 	
		  The post "Summary of Kolb database" says 35% of the poll participants use vortex generators in their machines.



Can somebody provide figures on the their aircraft weight and stall speed

before and after installing the VGs?



I am asking because I am interested in a project, (not a Kolb, sorry,)

that could be flown as a legal Part-103 ultralight if I can bring down the

stall speed.



Thanks,



Roberto Waltman 	




Here is my experience -

http://www.bcchapel.org/pages/0003/Vortex%20Generators.html



http://www.bcchapel.org/pages/0003/FSII%20Vortex%20Generators.html



Recently looked at Beauford's Firefly and his VG setup, consequently will be going to the little plastic triangular store bought VG's when we rebuild the FSII as he has found them to work better than the homemade ones.



Hope this helps -

Richard Pike

MKIII N420P (420ldPoops)

beauford

Joined: 25 Apr 2007
Posts: 127
Location: Brandon, FL

Posted: Tue Sep 08, 2009 2:45 pm Post subject: Re: Vortex Generators

Brother Waltman:

Despite Brother Pike's reference to improvements from the VG's, still getting mixed results and experimenting with the placement.  Not totally satisfied that these things work that well. Am currently back 11.5 inches from the leading edge, (see photo) but thinking of reducing this to about 10 inches.  Have some more testing planned with yarn tufts to see where the boundry layer is breaking away...



You mentioned that your machine wasn't a Kolb... What kind of airfoil are you working with...?



beauford

FF-076

VGinstall.jpg.JPG

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Viewed:

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slyck(at)frontiernet.net
Guest

Posted: Tue Sep 08, 2009 4:44 pm Post subject: Vortex Generators

bad boy.



On 8, Sep 2009, at 6:45 PM, beauford wrote:



 	  Quote: 	
		   



 Brother Waltman:

 Despite Brother Pike's reference to improvements from the VG's,  

 still getting mixed results and experimenting with the placement.   

 Not totally satisfied that these things work that well. Am  

 currently back 11.5 inches from the leading edge, (see photo) but  

 thinking of reducing this to about 10 inches.  Have some more  

 testing planned with yarn tufts to see where the boundry layer is  

 breaking away...



 You mentioned that your machine wasn't a Kolb... What kind of  

 airfoil are you working with...?



 beauford

 FF-076





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 62133#262133





 Attachments:



 http://forums.matronics.com//files/vginstalljpg_554.jpg

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Tue Sep 08, 2009 4:47 pm Post subject: Vortex Generators

Beauford,

     I put my first 7 VG's on the  ribs at 11 inches, and got a 5 or so MPH reduction in stall. I decided to  put 7 more of them evenly in between the ribs at 10 inches and obtained an equal  amount of stall reduction, which lead me to believe that 10 inches would be the  better place to install them. I think if you figure the percentage that is  recommended of 10 percent comes out closer to 10 than 11 inches.

 Like you say- " worth what you paid for it"

 Larry C

  

  

 [quote]   ---

_________________
do not archive

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Tue Sep 08, 2009 6:18 pm Post subject: Vortex Generators

OOOOOOOOOOOPS! snookered again.

 Larry C

 [quote]   ---

_________________
do not archive

beauford

Joined: 25 Apr 2007
Posts: 127
Location: Brandon, FL

Posted: Tue Sep 08, 2009 6:24 pm Post subject: Vortex Generators

Yes... I know...  guilty as charged, Brother Bean... bad boy...



The photo is an old gag... although I'll bet someone has tried them down there...



Brother Waltman:

The Landshorter clear lexan VG's Brother Pike referred to seeing when he was 

visiting are right up on top of the wing at 10% of chord exactly where the LS 

people said to put them.  Substantial performance improvement over the homemade 

aluminum jobs, which were at 11.5 inches.  I don't have the exact measurement at 

hand, but the Landshorters are roughly 2.5 inches forward of where the old 

aluminum ones were.



The Fly actually feels a tad floaty with the Landshorters...  vice the previous 

imitation of a lawn dart it wanted to execute when the power was chopped before. 

The aluminum VG's helped some, and were definitely better than nothing, but the LS 

installation really changed the game.  It now gives a pretty fair power-off glide 

at 46 or so indicated ... before, at anything below 50 it seemed as if you would 

be looking almost between your feet at where the impact crater was likely to be. 

No real change in the stall personality...still a mild non-event at normal 

acceleration... just a few mph slower than before. There is a real improvement in 

the landing flare in ground effect... again, more bouyant.  I like 'em.  To me, 

anything which can extend the dead-stick glide and slow the terminal arrival speed 

of an airplane powered by a single-ignition, 2-stroke Nazi engine is a worthwhile 

insurance item.



'Ol bad beauford is going to now punish himself for posting the gag picture by 

going to bed without any (more) supper.... although he may get himself just a 

taste of cheap brandy and a Cusano 18 stogie and sit out back a while before 

bed...no sense in going Draconian over this...  He'll be meditating about paper 

VG's...



..worth what ye paid fer it, Brother Waltman...



beauford

FF-076

Brandon, FL

Do Not Archive



---

aslsa.rng(at)gmail.com
Guest

Posted: Tue Sep 08, 2009 6:52 pm Post subject: Vortex Generators

Okay, Beauford, that was just rude.  On a more serious note, has anyone read the Wind Tunnel column in the new issue of Kitplanes?



Rick Girard



On Tue, Sep 8, 2009 at 9:27 PM, Beauford T <beauford173(at)verizon.net (beauford173(at)verizon.net)> wrote:

 [quote]--> Kolb-List message posted by: "Beauford T" <beauford173(at)verizon.net (beauford173(at)verizon.net)>

  

 Yes... I know...  guilty as charged, Brother Bean... bad boy...

 

 The photo is an old gag... although I'll bet someone has tried them down there...

 

 Brother Waltman:

 The Landshorter clear lexan VG's Brother Pike referred to seeing when he was

 visiting are right up on top of the wing at 10% of chord exactly where the LS

 people said to put them.  Substantial performance improvement over the homemade

 aluminum jobs, which were at 11.5 inches.  I don't have the exact measurement at

 hand, but the Landshorters are roughly 2.5 inches forward of where the old

 aluminum ones were.

 

 The Fly actually feels a tad floaty with the Landshorters...  vice the previous

 imitation of a lawn dart it wanted to execute when the power was chopped before.

 The aluminum VG's helped some, and were definitely better than nothing, but the LS

 installation really changed the game.  It now gives a pretty fair power-off glide

 at 46 or so indicated ... before, at anything below 50 it seemed as if you would

 be looking almost between your feet at where the impact crater was likely to be.

 No real change in the stall personality...still a mild non-event at normal

 acceleration... just a few mph slower than before. There is a real improvement in

 the landing flare in ground effect... again, more bouyant.  I like 'em.  To me,

 anything which can extend the dead-stick glide and slow the terminal arrival speed

 of an airplane powered by a single-ignition, 2-stroke Nazi engine is a worthwhile

 insurance item.

 

 'Ol bad beauford is going to now punish himself for posting the gag picture by

 going to bed without any (more) supper.... although he may get himself just a

 taste of cheap brandy and a Cusano 18 stogie and sit out back a while before

 bed...no sense in going Draconian over this...  He'll be meditating about paper

 VG's...

 

 ..worth what ye paid fer it, Brother Waltman...

 

 beauford

 FF-076

 Brandon, FL

 Do Not Archive

 

 

 

 

 

 ---

apilot(at)surewest.net
Guest

Posted: Tue Sep 08, 2009 7:45 pm Post subject: Vortex Generators

My VG's are at about 11 inches back on my Mk III Classic.  This location is based on the highest tangent line when the wing is at cruise attitude (about 7 degree).  They work good, but I believe that they would produce a slower stall if they were on the top tangent of the airfoil when the angle of attack is at stall speed.  Also, it is my opinion that I should have put them in the valleys between the ribs and not on the ribs.  At any rate, I like them and it has saved my stock landing gear legs several times.  Now that I have achieved a smooth tail wheel first landing, I plan to do most of my landings on the main gear.  I cannot remember an airplane than I enjoyed flying more than my old Classic.  It is for sale, but not because I don't like it.  Vic  N4201G

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Wed Sep 09, 2009 4:53 am Post subject: Re: Vortex Generators

The least expensive source I've found for plastic manufactured VGs is at the following link.



http://flyfbi.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=FS&Product_Code=AIRWAVE-100&Category_Code=ACS



or 



http://tinyurl.com/mp76ay



I have some home made aluminum ones that I was going to put on my SS but since Beauford said the Landshorter ones work better than the aluminum ones did on his Kolb, I'm considering ordering a set of these.

_________________
Thom Riddle
Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
- Anonymous

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Wed Sep 09, 2009 6:47 am Post subject: Vortex Generators

> I have some home made aluminum ones that I was going to put on my SS but 

since Beauford said the Landshorter ones work better than the aluminum ones 

did on his Kolb, I'm considering ordering a set of these.

 	  Quote: 	
		  

 Thom Riddle


	


Hi Gang:



I was looking at the VG ad from Thom R.  Kit includes 100 each VGs.  Without 

going to Land Shorter web site, I believe they also send 100 VGs in their 

kit.



 	  Quote: 	
		  From the above info,  am I to assume all airplanes use the same number of 

VGs? i.e., Fire Fly with 22 foot wingspan uses same number as MKIII with 30 
	


feet?



john h

MKIII

West Yellowstone, MT

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

rwaltman

Joined: 12 Aug 2009
Posts: 5

Posted: Wed Sep 09, 2009 9:04 am Post subject: Vortex Generators

Thanks for all the responses.



The project in question was a Colomban CriCri, now in eBay:



http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300343336101&viewitem=&sspagename=STRK%3AMEWAX%3AIT



I played for a while with the idea of buying it, and build a pair of

slightly longer wings to shoehorn it into Part-103 limits.

(Stock stall speed is too high for VGs alone to bring it down to '103

specks - would be non-aerobatic, of course.)



Between the longer wings + VGs + new propellers to limit max speed, it

could have been a wonderful '103 plane.



Fortunately, I suffered an attack of temporary sanity and begun to think

about the side effects of such change. Longer wings will develop more

lift,  but what about elasticity problems? Do I want to do flutter testing

with the new wings? (Answer: No)

The tail surfaces may not have enough control authority at lower speeds

making landings tricky.

Also, flying at lower speeds and higher angle of attack will make the

T-tail sink into the turbulence created by the fuselage and canopy. Again,

potential control problems at low speeds.



Finaly, I could fit in that plane, but me and my wife together would not.

So I am back looking for a two-seat LSA, may be a Kolb.



Sorry for the detour from the regular programming and again, thanks for

the very useful information shared here.



Roberto Waltman

_________________
Roberto Waltman

beauford

Joined: 25 Apr 2007
Posts: 127
Location: Brandon, FL

Posted: Wed Sep 09, 2009 1:22 pm Post subject: Vortex Generators

 	  Quote: 	
		  >From the above info,  am I to assume all airplanes use the same number of

>VGs? i.e., Fire Fly with 22 foot wingspan uses same number as MKIII with 30

>feet?


	


--------

..Well...I reckon you COULD get all 100 of 'em on the Fly, John...   but it might 

look kinda like a cheese grater from the front.... and would likely sound like a 

harmonica band going by...



Actually, the Landshorter package provides an assortment of templates to make sure 

that the installer sets them on the wings of a given airplane at an efficient 

interval and exactly the right angle of attack...they make a big deal of getting 

the angle of attack of the VG precisely correct, and the templates will do that if 

one pays attention to them. I had about 28 of the original 100 left over on the 

Fly as I recollect.  When I ordered them the lady at Landshorter mentioned that 

while most folks just keep the extras as spares in the event some fall off,  she 

said that some customers who have shorter wingspan machines use the leftovers at 

other places such as the tail feathers...  I decided to leave the  old aluminum 

items currently on the bottom of the horizontal stab and both sides of the 

vertical stab on the Fly where they are... mainly because they are danged hard to 

get off, even after soaking.  I tried.  I'll keep about 8 of the Lexan extras in 

case I eventually lose a few off the wings... will likely replace the five large 

yellow ones on the helmet with the remaining 20...



Speaking of losing them... I have yet to have a single one of the Lexan units fall 

off...  Landshorter recommends a certain Loctite #401 industrial-strength 

cyanoacrylic clear cement, basically a souped-up crazy glue, to put them on 

with... they sell the stuff and I ordered a tube with my VG's.   One thing, 

though --  one had best know EXACTLY where, and at what angle, one wants that 

doober BEFORE it touches to the fabric...or your thumb.... your stogie... the 

cat.... your left nostril..... whatever.  The word "adjustment" is clearly not in 

the Loctite #401 vocabulary....even one nanosecond after first contact.  Kinda 

reminded me of our honeymoon....



So far -- So good,  with these things...  as already mentioned,  a remarkable 

positive difference from the VG setup I previously had...



..worth what ye paid fer it...



beauford

FF-076

Brandon, FL

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Wed Sep 09, 2009 1:55 pm Post subject: Vortex Generators

I had about 28 of the original 100 left over on the

 	  Quote: 	
		   Fly as I recollect.



 beauford


	




Beauford/Gang:



Still don't know if I would have enough left over for my helmet after 

fitting out the MKIII wing.  ;-(



john h

mkIII

West Yellowstone, MT - 24F this morning when I got up, but T-shirt weather 

under a dark blue cloudless sky this afternoon.  Just got up from my nap and 

headed out to find me some senior citizen grub.

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

mdnanwelch7(at)hotmail.co
Guest

Posted: Wed Sep 09, 2009 2:16 pm Post subject: Vortex Generators

John C 

  

   You have the priority backwards.  FIRST C the helmet C then the wings.  : )

  

 Mike Welch

 MkIIICX

 

[quote] From: jhauck(at)elmore.rr.com

 To: kolb-list(at)matronics.com

 Subject: Re: Re: Vortex Generators

 Date: Wed C 9 Sep 2009 15:30:57 -0600

 

 --> Kolb-List message posted by: "John Hauck" <jhauck(at)elmore.rr.com>

 

 

 I had about 28 of the original 100 left over on the

 > Fly as I recollect.

 >

 > beauford

 

 

 Beauford/Gang:

 

 Still don't know if I would have enough left over for my helmet after 

 fitting out the MKIII wing. ;-(

 

 john h

 mkIII

 West Yellowstone C MT - 24F this morning when I got up C but T-shirt weather 

 under a dark blue cloudless sky this afternoon. Just got up from my nap and 

 headed out to =====================

 _=====

 

 

 

With Windows Live C you can organize C edit C and share your photos. Click here.   	  Quote: 	
		  [b]

JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Fri Sep 11, 2009 1:39 pm Post subject: Re: Vortex Generators

 	  Richard Pike wrote: 	
		  



Recently looked at Beauford's Firefly and his VG setup, consequently will be going to the little plastic triangular store bought VG's when we rebuild the FSII as he has found them to work better than the homemade ones.



Hope this helps -

Richard Pike

MKIII N420P (420ldPoops) 	




I have been posting the above information about VG's here on the list for the last 3 years, telling people that they were critical in design and placement, and to just spend the 100 dollars on ones that are designed properly and will perform best,  you just now figured this out ???



Mike

_________________
"NO FEAR" - If you have no fear you did not go as fast as you could have !!!

Kolb MK-III Xtra, 912-S

zeprep251(at)aol.com
Guest

Posted: Fri Sep 11, 2009 2:08 pm Post subject: Vortex Generators

Richard,

  That didn't take very long, did it?

 

   G.Aman

 

   

 

 --

jlsk1(at)frontiernet.net
Guest

Posted: Fri Sep 11, 2009 4:24 pm Post subject: Vortex Generators

I like my MK-3 the way it is.(Keeping this Kolb  related) (Smiles)

 Leopards don`t change spots.

 Do not archive

 Jim Kmet MK-3C

 [quote]   ---

aslsa.rng(at)gmail.com
Guest

Posted: Fri Sep 11, 2009 4:53 pm Post subject: Vortex Generators

Well, not to be a contrarian, but I'm going to Agent Orange for some plastic angle tomorrow and make them per the latest Wind Tunnel column in Kitplanes. Cheap thrills. Okay, every body have your finger poised on the Delete key.  

 



Rick Girard



On Fri, Sep 11, 2009 at 7:18 PM, Jim Kmet <jlsk1(at)frontiernet.net (jlsk1(at)frontiernet.net)> wrote:

[quote]        I like my MK-3 the way it is.(Keeping this Kolb  related) (Smiles)

 Leopards don`t change spots.

 Do not archive

 Jim Kmet MK-3C

 [quote]   ---

zeprep251(at)aol.com
Guest

Posted: Fri Sep 11, 2009 5:35 pm Post subject: Vortex Generators

Rick, Tender subject I know,but I have the Landshorter VGs on my MK-3,but never had them on the Firestar,and granted they are two different airplanes,BUT,solo the MK stalls in the 20's and the FS2 at 36 and the break is gentle in the MK when it quits.BUT they were on it when I got it.The guy I bought it from had a 2" thick file on VG's and had really investigated before he bought and installed them.I'm interested to see your results -before and after.

          G.Aman

 

 

 

   

 

   

 

 --

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