Today's Message Index:
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1. 09:41 AM - Re: KIS TR-1 Airfoil (Propellerjan)
2. 05:44 PM - Re: Re: KIS TR-1 Airfoil (Mark Kettering)
3. 09:10 PM - Re: Re: KIS TR-1 Airfoil (Scott Stearns)
Message 1
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| Subject: | Re: KIS TR-1 Airfoil |
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
Message 2
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| Subject: | Re: KIS TR-1 Airfoil |
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
-----Original Message-----
>From: Propellerjan <propellerdesign@tele2.se>
>Sent: Jan 25, 2013 12:40 PM
>To: kis-list@matronics.com
>Subject: KIS-List: Re: KIS TR-1 Airfoil
>
>
>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
>
>
Message 3
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| Subject: | Re: KIS TR-1 Airfoil |
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@tele2.se> wrote:
>
> 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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