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sstearns2(at)yahoo.com
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 Posted: Tue Jan 15, 2013 9:52 am Post subject: KIS TR-1 Airfoil |
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That is how I read it too. Even fighting a fully nose down trim I don't think you could get to a stick force of over 100 pounds in either airplane.
Scott
From: Propellerjan <propellerdesign(at)tele2.se>
To: kis-list(at)matronics.com
Sent: Tuesday, January 15, 2013 9:10 AM
Subject: Re: KIS TR-1 Airfoil
--> KIS-List message posted by: "Propellerjan" <propellerdesign(at)tele2.se (propellerdesign(at)tele2.se)>
Yes a range of aloud ables.
as I understand it, if the in case of elevator the air load will give a stick load of 200 use 167, if it is 120, use 120, if it is 90 use 100.?
Jan
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Thu Jan 24, 2013 5:14 am Post subject: Re: KIS TR-1 Airfoil |
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I got the late Harry Riblett GA AIRFOILS Book the other day.
He has some really good information and fixes in his book, and the story about how he comes
to develop his own airfoils the GA- series.
In the book is a “quick fix” for the NACA 64-212 with a cuff going 10% of the chord on
bottom surface.
Instead of the super elevation LE of the NACA, he draws in a 12 degree initial camber angle
and a new mean line that create the cuff. The good with this mod is that it maintain the
laminar flow. Not so with VG’s
This cuff on the KIS-1 will be about 8 mm forward and little more thickness under the nose, a
little to much for a “micro” job, but hot-wire foam inlay and glass, or pre- molded will work.
He also show that the flap top should have a raised and curved surface, this is not really new it
have been used on many plane since before the WW2, but by making the control surface
thicker then the true airfoil, it re-energize the air, so it follow better and also have less drag,
almost as there was no gap from beginning.
This will work on the elevator as well, but then at the bottom.
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Flyinisfun(at)aol.com
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| Posted: Thu Jan 24, 2013 5:27 am Post subject: KIS TR-1 Airfoil |
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Not being an aeronautical engineer, could you draw me a picture of what this looks like? I'm very interested to know more.
Jesse Wright
In a message dated 1/24/2013 6:14:52 A.M. Mountain Standard Time, propellerdesign(at)tele2.se writes:
| Quote: | --> KIS-List message posted by: "Propellerjan" <propellerdesign(at)tele2.se>
I got the late Harry Riblett GA AIRFOILS Book the other day.
He has some really good information and fixes in his book, and the story about how he comes
to develop his own airfoils the GA- series.
In the book is a “quick fix†for the NACA 64-212 with a cuff going 10% of the chord on
bottom surface.
Instead of the super elevation LE of the NACA, he draws in a 12 degree initial camber angle
and a new mean line that create the cuff. The good with this mod is that it maintain the
laminar flow. Not so with VG’s
This cuff on the KIS-1 will be about 8 mm forward and little more thickness under the nose, a
little to much for a “micro†job, but hot-wire foam inlay and class, or pre moulded will work.
He also show that the flap top should have a raised and curved surface, this is not really new it
have been used on many plane since before the WW2, but by making the control surface
thicker then the true airfoil, it re-energize the air, so it follow better and also have less drag,
almost as there was no gap from beginning.
This will work on the elevator as well, but then at the bottom.
--------
www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392991#392991
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http://forums.matronics.com//files/naca_63a215_nosejob_125.jpg
http://f ies ay - MATRONICS WEB FORUMS - List Contribution Web Site p;
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Thu Jan 24, 2013 5:58 am Post subject: Re: KIS TR-1 Airfoil |
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I did, you can not see them? 3 jpeg attached in the forum.
Jan
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galinhdz(at)gmail.com
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| Posted: Thu Jan 24, 2013 6:28 am Post subject: KIS TR-1 Airfoil |
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No I couldn't see them. :0(
On Thu, Jan 24, 2013 at 7:58 AM, Propellerjan <propellerdesign(at)tele2.se (propellerdesign(at)tele2.se)> wrote:
[quote]--> KIS-List message posted by: "Propellerjan" <propellerdesign(at)tele2.se (propellerdesign(at)tele2.se)>
I did, you can not see them? 3 jpeg attached in the forum.
Jan
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www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392995#392995
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Thu Jan 24, 2013 6:49 am Post subject: Re: KIS TR-1 Airfoil |
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you have my e-mail there os go to my home page, and send your e-mail and I mail them to you,
Jan
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Robert Reed
Joined: 22 Oct 2009
Posts: 331
Location: Dallas/Ft.Worth
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| Posted: Thu Jan 24, 2013 7:27 am Post subject: KIS TR-1 Airfoil |
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Galin,
Clickon the following which was at the bottom of the posting:
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392995#392995
From: Galin Hernandez <galinhdz(at)gmail.com>
To: kis-list(at)matronics.com
Sent: Thu, January 24, 2013 8:28:55 AM
Subject: Re: Re: KIS TR-1 Airfoil
No I couldn't see them. :0(
On Thu, Jan 24, 2013 at 7:58 AM, Propellerjan <propellerdesign(at)tele2.se (propellerdesign(at)tele2.se)> wrote:
[quote]--> KIS-List message posted by: "Propellerjan" <propellerdesign(at)tele2.se (propellerdesign(at)tele2.se)>
I did, you can not see them? 3 jpeg attached in the forum.
Jan
--------
www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392995#392995
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Flyinisfun(at)aol.com
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| Posted: Thu Jan 24, 2013 6:06 pm Post subject: KIS TR-1 Airfoil |
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Jan, Would this mod change the flight envelope, move it, widen it or what? Since it would increase lift, would it up the useful load? Thanks for your reply.
Jesse Wright
In a message dated 1/24/2013 8:27:06 A.M. Mountain Standard Time, robertr237(at)att.net writes:
[quote][b]
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Thu Jan 24, 2013 7:11 pm Post subject: Re: KIS TR-1 Airfoil |
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I will test it in virtual wind tunnel, and we see if it as good as Mr. Riblett say, what we can see is that the nose is corrected and this lead to increased camber, as seen the original nose is above the chord line, meaning it have less camber and initial mean line slope then the original mean line it self, due to the way Naca place the original uncambered airfoil 63A015 along the mean camber line.
more camber give more lift and higher max CL, but due to the change in camber is at the first 10% the negative moment in unchanged.
the dropped nose will increase the stall angle.
It is late here, but I will pick the coordinates out tomorrow, and see what the DesignFoil program say. but as with all computer program they are poor at detached flow.
Jan
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Fri Jan 25, 2013 9:40 am Post subject: Re: KIS TR-1 Airfoil |
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Hi Al'
this is analyze of the KIS-1 airfoil, not the 4-Cruiser that have a different
airfoil the N-65-415
I tested the Naca 63A215-Coff'd airfoil in 3 airfoil program, DesignFoil,
JavaFoil and X-foil.
in all 3 I got lower drag with the coff's airfoil.
In DesignFoil the max lift was lower with coff, sounds strange.
the other show higher CLmax with the coff as expected.
I have not used X-foil before so downloaded it and made some test runs, still more to learn there. but nice thing when can run 2 or more airfoils at the same time, and see the difference. Absolute numbers should we take with a grain of salt, but side by side runs, show the difference.
at the end I run it with GA 37315 that really outperform 63- series with and without cuff.
the pure 63A215 seems to have a peculiar behavior at 5-6 degree of angle, where the -moment all of a sudden increase with increased angle, will lead to a nose down force. this is gone with the cuff.
in all, the cuffed airfoil will have less drag, except at lower CL then 0,3 where it start to get more drag when bottom is going from laminar to turbulent flow, if we/you don't "cruise" WOT at or below Sea level all the time, it have little practical importance, at 75% or less, and higher alt the cuff'd airfoil will win.
the computer programs and theory say that, it will have higher CLmax, lower drag, better climb. And looks like it will have a gentler stall, and probably work better with flaps.
Any takers on real "wind tunnel" flying testing?
If it can carry more weight? I say that is a question of wing strength. and power. See attached pictures, there is 2 Re. numbers for each airfoil, 2 and 6 mil. (stall and cruise) one pic with 63A plane and with cuffs, and one pic with the GA 37A315.
Jan
Ps. any comments welcome. 
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mantafs(at)earthlink.net
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| Posted: Fri Jan 25, 2013 5:44 pm Post subject: KIS TR-1 Airfoil |
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Hello Jan,
Thanks for doing the KIS TR-1 airfoil analysis. I think this is really helpful and useful.
But maybe I am reading the graphs incorrectly. To me it looks like the original airfoil is the best given the cruise speed, weight and wing plan of the TR-1. For example a fairly clean TR-1 with a 160 hp Lyc should be able to cruise at about 170 knots TAS at 8.5kmsl and 75%. This gives a CL of about 0.21 at 1450 gross. My O-235 powered TR-1 will cruise at about 155 knots TAS at 8.5kmsl and 75%. This gives a CL at gross of 0.26. Scott's IO-360 powered TR-1 will cruise at better (much better?) than 190 knots TAS. This gives a CL of under 0.17. At all of these CLs it looks like the stock wing has the best CL/CD. If you are below max gross the CL's are even lower and the stock wing is even better.
I also know that many do not cruise at 75%. But many also do not fly at gross. Much of the time I have flown was with 1 person and half fuel. With my O-235 powered TR-1 the CL would be under 0.2 at similar cruise solo. Even with just 65% power the cruise is about 145 knots TAS with a CL of about 0.23. The stock airfoil still looks like it has the least drag.
I know drag at cruise is not the whole story but you do spend most of the time in cruise. The climb and stall speed could be slightly better with the other airfoils.
I am not at all saying that the 63A215 airfoil is the best. Nor that with a smaller wing the other airfoils could work better. But it looks to me that you will reduce cruise speed with the cuff or the other airfoil is you keep the same wing and same gross.
Mark
--
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sstearns2(at)yahoo.com
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| Posted: Fri Jan 25, 2013 9:10 pm Post subject: KIS TR-1 Airfoil |
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Also keep in mind that the 63A215 airfoil is quite different at the trailing edge then what is on the airplane. The airplane just has a triangular section for the last 20% or so whereas the 63A215 has a lot of undercamber and the upper and lower surfaces are near parallel at the trailing edge. The discontinuity is significant from the wing to the flap and aileron.
Scott
On Jan 25, 2013, at 9:40 AM, "Propellerjan" <propellerdesign(at)tele2.se> wrote:
| Quote: |
Hi Al'
this is analyze of the KIS-1 airfoil, not the 4-Cruiser that have a different airfoil the N-65-415
I tested the Naca 63A215-Coff'd airfoil in 3 airfoil program, DesignFoil, JavaFoil and X-foil.
in all 3 I got lower drag with the coff's airfoil.
In DesignFoil the max lift was lower with coff, sounds strange.
the other show higher CLmax with the coff as expected.
I have not used X-foil before so downloaded it and made some test runs, still more to learn there. but nice thing when can run 2 or more airfoils at the same time, and see the difference. Absolute numbers should we take with a grain of salt, but side by side runs, show the difference.
at the end I run it with GA 37315 that really outperform 63- series with and without cuff.
the pure 63A215 seems to have a peculiar behavior at 5-6 degree of angle, where the -moment all of a sudden increase with increased angle, will lead to a nose down force. this is gone with the cuff.
in all, the cuffed airfoil will have less drag, except at lower CL then 0,3 where it start to get more drag when bottom is going from laminar to turbulent flow, if we/you don't "cruise" WOT at or below Sea level all the time, it have little practical importance, at 75% or less, and higher alt the cuff'd airfoil will win.
the computer programs and theory say that, it will have higher CLmax, lower drag, better climb. And looks like it will have a gentler stall, and probably work better with flaps.
Any takers on real "wind tunnel" flying testing?
If it can carry more weight? I say that is a question of wing strength. and power. See attached pictures, there is 2 Re. numbers for each airfoil, 2 and 6 mil. (stall and cruise) one pic with 63A plane and with cuffs, and one pic with the GA 37A315.
Jan
Ps. any comments welcome.
--------
www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=393035#393035
Attachments:
http://forums.matronics.com//files/x_foil_analyze_194.jpg
http://forums.matronics.com//files/x_foil_analyze_3_foils_979.jpg
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Sat Jan 26, 2013 2:13 am Post subject: Re: KIS TR-1 Airfoil |
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Thank's Mark and Scott good points.
Yes it give more drag with the cuff at speeds higher then the CL 0,3 as I wrote in previous post. and I realize it is not for Scott's light and fast plane.
To the "pure" CL given from weight, speed and density alt, we have to ad 0,02- 0,03 due to tail down force. (about 10%)
There is 2 NACA 63-215 airfoils, the one with a A is the one used on the KIS-1 this is the one without cusp, straight or almost straight upper and lower rear surface. said to have 0,0002 Cd more then the cusp'd airfoil, (like a mosquito shit on the LE) but simpler, more structure and more effective ailerons with the A model. this is the basic airfoil I used in this example.
The related Riblett airfoil would be GA 35A215, it is using Ribletts mean line and NACA 63A015 thickness distubution.
I am curious how much drag the modified wing with cuff will make, say at WOT 8000´I0-240, 1450 lb, My Propeller software say 179 mph 155kts TAS, thats what you guys say too, CL 0,25+0,02 = 0,27
The total drag will be 80 kg/ 176 lb.
the delta drag coefficient from the cuff is at CL. 0,27 = 0,000857 if the X-foil program is correct.
with the exposed wing area this give a Fo of 0,00594 m2 (sorry for using metric system) the q is 314,3 kg/m2 and then delta drag is 1,86 kg
at 175 mph q is 300,4 = drag is 1,78 kg
so new speed will be 174-175mph/151-152 kts
BUT at that speed CL is 0,27 + 0,02 = 0,29 where the drag penalty is less then half of what it is at CL 0,27, so real slow down 1,5-2 kts.
At faster speeds the drag penalty will be higher!
The goal with the cuff isn't to reduce drag but enhance handling, slower stall speed, better climb, less erratic moment coefficient,
It is a quick fix for a faulty airfoil. if it paying off?
Flying slower than 150 mph IAS it will, maybe a cuff with half the LE drop will be better? I just used the example in the book. realising the concave spot under the nose where the cuff fair into the original airfoil would create drag at small alpha. and sure it did.
This have to be seen in relationship to the drag with VG's on the wing, any one with real numbers?
Jan
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Last edited by Propellerjan on Sat Jan 26, 2013 9:29 am; edited 2 times in total |
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Sat Jan 26, 2013 4:12 am Post subject: Re: KIS TR-1 Airfoil |
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Okay, always goes faster second time.
Riblett talks about his mean line have 0,3% nose drop on the CL 0,2 mean line, so I used that, and it is half of the first one.
Very interesting result.
I used single Re Nr. 2 and 6 million. 47,5 & 143 kts SL to make the graph clear, and zoomed in the interesting parts at the speeds
at 2 mill the original and the full cuff airfoils polar curve just stop at CL 1,2 and 1,4 but not the half cuff, why i don't know. maybe the half cuff is good?
at Re 6 mill the half cuff have half the drag penalty of the full cuff at CL 0,15 and brake even at 0,25 with original airfoil.
And hardly any measurable penalty at CL .2 (,17+,03)
at CL 0,6 the half cuff is better.
Higher CLmax at higher alpha, and Cm curve more even.
Okay good exercise.
Jan
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Sun Jan 27, 2013 3:34 am Post subject: Re: KIS TR-1 Airfoil |
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I made a "final" test with original NACA 63A215, Half-Cuff on the same airfoil and the Riblett GA 35A215, all these have the same basic symmetric airfoil, except the Half-Cuff that is modified under the LE, The NACA and the Half-Cuff have the same mean line, except at the nose of the Half-Cuff, the GA have the Riblett GA-2 mean line.
It is seen that the Riblett will have a "softer" stall, seen on the more rounded polar curve at stall, meaning the stall will be more like a mush then a sharp stall.
The Half-Cuff will have almost as low stall speed as the Riblett, but little sharper stall, but what happens to the N-63 at low speed? laminar bubble that burst?
The Half-Cuff will be like a in-plant for the KIS, and VG's will be more like a band-aid.
Nothing wrong with the KIS-TR1 that can't be fixed.
Why did I do this? because I read that so many if not all have issues with landings and it have to be landed precise at a almost constant angle at approach.
Please correct me if I am wrong, I have not flown the KIS
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mantafs(at)earthlink.net
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| Posted: Sun Jan 27, 2013 10:04 am Post subject: KIS TR-1 Airfoil |
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Hello Jan,
As far as I know there are 3 issues with landing the TR-1. The pitch control is very light. I think the best two fixes for this are increase the cord of the elevator by adding 1 to 2 inches to the trailing edge and maybe changing the control ratio. The second is lack of control power when at or near forward CG. Adding to the elevator cord helps and and slightly increasing the travel helps. The travel can be increased via changing the control ratio. The third landing issue is the nose slamming down after touchdown. This is due to the main gear being too far aft and is simple to correct by slightly angling the main gear legs forward. This also helps to solve 2 other problems, the over rotation on liftoff and the high loads on the nose gear.
Anytime you reduce the stall and landing speed it is good. But any time you reduce the cruise speed and the VNO it is bad. It is less simple to change the good without changing the bad at the same time when using fixed aerodynamic changes. Of course to some the slow speed numbers are more important but at least for me the high speed numbers are more important as long as the low end meets my minimums.
What other landing issue have others had with the TR-1 and TR-4?
Thanks,
Mark
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Sun Jan 27, 2013 1:02 pm Post subject: Re: KIS TR-1 Airfoil |
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Hi Mark,
I see you know a lot on this and about the KIS, I am new to this forum, so I don't know your background so please fill me in a little.
I hope I didn't step on anyones toes here.
When I write, I try to make it understandable for all, pilots, homebuilders or engineers.
Some things is obvious for some people, but news for others.
I fully understand the need for speed, designing optimal propellers as I am.
As in the example with the full first cuff, loosing 2 kts might not seen much but 1-1,5% speed is the same as 3-4,5% thrust power.
(and the other way around)
On the other hand 1 kts might be within reading and instrument error.
I understand there is issues with horizontal tail volume, as I wrote in the first posts in this thread, where the original tailplane and elevator is to small, with a TV of 0,49 -0,50 depending on CG.
elevator is recommended to be 35-45% of chord, and original is 36%
and recommended TV would be 0,6 in a 2 place with flaps.
but TV is not any absolute numbers, NP and stability margin say more.
More elevator area will move the forward cg limit forward, or some nose down on the stab, but the same time we want the elevator to be in line with stab in cruise.
Larger stab and elevator will move the rear cg limit back, or increase stick force gradient. so making the elevator larger is a good thing, nothing new there. 2,5" extra will make the elevator 42% of total chord. and increase tail area with 10% and a TV of 0,55.
Even a larger H-tail area seems to be needed, those changes above move the cg limit maybe one % each direction, but a larger area will ad drag too.
But we had covered that before.
What I read between the lines when it comes to deployed flaps, is that they hardly make any difference in stall speed? is that right? and don't change the moment either, until VG's is installed on the wing?
That make me think there is something fishy with the original airfoil, if that can be fixed without adding drag like VG's will do I think it is a good thing, I understand that higher CL will lower stall speed as well as Va and Vno, but the change will be small,
Today is the Vno calculated from real world stall speed or theoretical? if the latter, a correction of the airfoil will probably not change anything.
The biggest change will be in stall speed with flaps, and that will not change Vno nor Va.
What I can read in this forum is that most pilots would like to have a better handling and a honest airplane that behave the same every time.
I am not saying it is the single problem, but as seen in the "wind tunnel" test the 63A215 change its Cm rapidly at 4-5 deg alpha, meaning something is happening there, I understand all 3 airfoils goes from laminar to turbulent about this angle too. but if there is a bubble that form and burst it will probably give the result that the flap don't work as a flap but as a air brake only.
The GA-35A215 isn't the same airfoil of the GA-family I tested, this seems to be no more draggy at any speed compared to the original, top speed will more likely be the same, but climb speed and stall speed better up.
But all airplanes is a number of compromises, so somewhere we have to chose between good handling and speed.
Sincerely
Jan
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Propellerjan
Joined: 11 Jan 2013
Posts: 21
Location: Sweden
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| Posted: Thu Jan 31, 2013 5:10 am Post subject: Re: KIS TR-1 Airfoil |
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Mark and all,
After I got the GA-35 and 37 A215 typed in and checked in 3 airfoil program, I got to this conclusion:
Can not trust any program to 100 %, we can see differences though, and they are all the same in the different programs, Xfoil seems to be more sensitive for un-even coordinates, but good thing is the polars can be zoomed in and out.
I found the erratic in Cm on the N-63A215 airfoil in Xfoil to be due to the last half% of the chords coordinates was making a cone to almost zero thickness, when corrected to have some thickness as the other airfoils that erratic Cm curve (moment) was almost gone, the other programs like DesignFoil and JavaFoil don't seem to be so sensitive.
What I can see is that the GA35A215 will have the lowest drag, specially at climb, the GA-37A215 will have little higher max CL.
The GA- airfoils have a little rounder/softer stall.
The Half-Cuff will help on the N-63A215 as it seems, but have to be tested in real world.
Jan Carlsson
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