Today's Message Index:
----------------------
1. 09:27 AM - Re: KIS TR-1 Airfoil (Propellerjan)
2. 12:43 PM - Re: KIS TR-1 Airfoil (Mark Kettering)
3. 01:37 PM - Re: KIS TR-1 Airfoil (Scott Stearns)
4. 05:49 PM - Re: KIS TR-1 Airfoil (Mark Kettering)
5. 06:09 PM - Re: KIS TR-1 Airfoil (Flyinisfun@aol.com)
6. 07:10 PM - Re: KIS TR-1 Airfoil (Scott Stearns)
7. 07:47 PM - Re: KIS TR-1 Airfoil (Scott Stearns)
8. 07:53 PM - Re: KIS TR-1 Airfoil (Flyinisfun@aol.com)
Message 1
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Subject: | Re: KIS TR-1 Airfoil |
I put all data in from the KIS, with airfoil data, and the KIS handbook from Norway
using the original size of H-stab and elevator, and Hans Christan's forward
and most after CG load example into Neil Willford's excellent excel spreads.
the CG ended up exactly the same as in Hans Christan's book, good work both of
them.
with 5" stick travel (what is original layout?) I got little over the 4,4 lb/g
recommended as minimum, for this 4,4G aircraft with sticks.
the most forward CG with this setup with flaps was aerodynamically said to be right
at the forward limit 18% MAC, in ground effect and with flaps, so no margins
there. All dimensions for the H-stab and elevator is at the lower recommended
numbers, both the Tail volume Nr's with Fwd and rear CG Tv=0,49-0,50 ( 0,5
is recommended for single seat or 2-seat without flap, 0,7 for four seat, and
0,6 for 2-seat with flaps)
I then increased the H-tail to 17 sq/ft and elevator percent to 40% of the tail
chord, this moved the most forward CG limit possible to 16,2% MAC in ground effect
and with flaps, and stick force gradient up to about 6 lb/g
Aileron stick force with +- 12 deg. was something like 36 lb, also with 5" travel
each way. sounds heavy to me, but is what we can expect from those plates.
So much for theory, but it agree with what you guys learned from flying the KIS.
and the agreement was highly surprising but rewarding
it need bigger elevator and tail volume.
Anyone have the original unmodified stick travel (at top) and yours if modified
?
Jan Carlsson
www.jcpropellerdesign.com
--------
www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392259#392259
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Subject: | Re: KIS TR-1 Airfoil |
>From my calculations when I worked for Tri-R, the elevator push pull tube was
undersized for it's length. Then talking with Vance it came up that the up throw
was well less than calculated due to contact between the push tube and horizontal.
The solution talked about was to put an additional idler well aft in
the fuselage and as low as possible and then the most aft tube would no longer
contact the horizontal. This would solve two issues at the same time.
I also like the idea of increasing the length of the control arm on the elevator
and changing the ratio on the current idler. This would reduce the load on
the push tube and increase the clearance from the tube to the horizontal.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:34 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
As far as I can tell it is stock as per the plans. Maybe that is why the VG's made
a significant difference. Galin
On Sun, Jan 13, 2013 at 2:12 PM, Mark Kettering <mantafs@earthlink.net> wrote:
Hello Galin,
Is your elevator linkage stock as per the plans or modified to allow for more up
elevator? I think this modification is very important and may prevent the need
for VG's. The stock method had the control tube hit the bottom of the horizontal
inside the tail before a reasonable up elevator deflection limit could
be reached.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:20 AM
Subject: Re: KIS-List: KIS TR-1 Airfoil
Jan; What do you mean when you say "Tape them with Tesa fabric tape on the bottom
side of the Hinge line, inside the elevator, inside the rudder, inside the
aileron, and bottom of the flap hinge line." Can you provide a photo of what you
mean? This sounds like a viable option for those of us that have flying airplanes
and can't re-work the wing/tail.
I used the VG's from Stolspeed.com on the elevator and they made a significant
improvement while landing my TR-4.
GalinN819PR
On Fri, Jan 11, 2013 at 4:36 PM, Propellerjan <propellerdesign@tele2.se> wrote:
KIS TR-1 Airfoil
In the search for information to calculate an optimum propeller for the KIS I0-240
I found a lot of information and thoughts about its handling especially during
landing.
When picking an airfoil for a airplane project that is about the last thing to
do before the design is set in stone. The wing area is determined in respect of
stall speed with flap arrangement.
When having MTOW, wing aspect ratio and wing area, we can calculate speed and lift
coefficient, CL
The speed we use for this will be where we spend most of the time, not stall speed
and not top speed, but climb and normal cruise speed. So in this range the
airfoil should have the lowest drag, if it was an airliner that spend most of
its time climbing and cruising at high altitude at low indicated speed it will
be at similar CL most of the time (but Mach Nr will play its roll)
All aircrafts that see any production see an increase in installed power and weight.
If this was in the design of the KIS from start I dont know, but the prototype
had a Limbach from start if understand it correctly, and several hundred
lbs less weight.
Most seem to have the I0-240B engine installed now and a MTOW of 1450 lb or so.
And it is cruising at around 140 kts. This give an lift coefficient, of around
CL 0.3 at cruise, it mean that an airfoil with higher camber would have been
better then the current N-63A215, where the 3:d last digit tell the designed
CL So it have an airfoil designed for higher speeds, but no meaning to have that,
no one cruise at WOT at SL, but most cruise at 65-75% power from 2000 to 8000
or 12000
The NACA 6x- series isnt the best with today standard, rumour says that the NACA
screwed up when publishing these new airfoils with a faulty design that they
could not take back.
An Harry Riblett GA-37A315 would be a better choice, it have gentler stall, and
will show less drag at both cruise and climb, The difference between Riblett
and NACA is that the nose radii is placed correctly on the Riblett. The Riblett
will have about 7-8% higher CLmax.
I draw up both airfoils for evaluation and when aligning the portion where main
and after spar will be, it is a different of 1 degree at the chord line. (From
nose radii to trailing edge)
The NACA is in Green
>From the main spar and back there is very little difference in shape, meaning
the lift at same angle will be about the same with this difference in angle
The chord line is just a reference line that is convenient to draw and measure,
but aerodynamically it is almost a fictive line, the important line or angle
of an airfoil is the zero lift angle, from this line the lift is generated if
it is given an angle to the relative wind, think of an symmetric airfoil where
the zero lift line and chord line is the same, and at alpha zero it will not
produce any lift.
An airfoil with camber will produce lift even if the chord line is at alpha zero,
or slightly negative, because the zero lift line will have a positive alpha
to the wind.
To make a cambered airfoil to produce zero lift, the nose have to be lowered until
the zero lift line is parallel to the wind, so an cambered airfoil is said
to have a zero lift angle of minus some degree depending of the camber, it can
be -1 to -6 degree on common airfoils and camber.
The NACA 63A-215 have a zero lift angle of -1.64 degree, and the Riblett GA-37A315
-2.14 degree.
A difference of 0.50 degree.
The lift slope Cl alpha is depending on the wing aspect ratio, for a AR of 6, the
slope of the lift curve is CL = 2Phi / 1+2/A2 = 2Phi / 1 + 2 / 6 = 4.71239
per radian
Or 4.71239 / 57.3 = 0.08224 per degree
The original wing is 3 degree up from chord line to fuselage reference line, so
if we fly it with the reference line horizontal the wing CL is 3 - -1.64 =
4.64 degree a 0,08224 = 0,38 CL.
The GA-37A315 will be 1 degree less measured at the chord line, so 2 - -2.14 =
4.14. so CL with fuselage level will be 0.34
It means that at higher speeds the nose down angle will be 0.5 degree less.
Lets say we cruse at 165 MPH TAS @ 8000 and 1450 Lb the CL will be 0.30 plus the
fact that the wing have to carry the down force from tail plane. Both airfoils
have a negative pitch moment of 0.05, the Riblett just a little more then the
NACA due to more camber.
The load at the tail is its moment times the wing chord and area, times dynamic
pressure.
Divided with tail length.
It will be about 84-85 lb down force at cruise if CG is at 25% chord
So the wing then will carry 1535 lb or CL 0.32
A CG further back will reduce negative lift and then reduce induced drag. (And
reversed.)
1450 lb at after limit will reduce down force at the tail with 10 lb
at forward limit it will ad 35 lb to a total lift the wing have to do of 1570 lb
or CL 0.33
A CG to forward and the elevator will not be able to hold the nose up with flaps,
to far back and it will be sensitive on the stick. Then we come into:
Nose drop at landing, sounds like ground effect, when closer to ground the down
wash from wing is flattened out, meaning the tail will have less down force.
With a horizontal stab area of just a bit over 17% of the wing area, seems small,
even if the tail arm is long.
One reason for the elevator not be up to the job can also be the tail incidence,
0.5 - 0.75 degree down might help. (but hard to fix that now)
Seems like, longer elevators chords is a good thing, 1,75 longer chord move the
hinge line to 60% chord/40% elevator. (about normal)
And VG's, seems to help, it means something is wrong from start, to small elevator
or wrong incidence. Or to small H.- tail area or all three.
The Wing Fuselage fairing should be expanding and 10% of the chord at the trailing
edge, according to Raymer, It mean in my eyes it should be 10% of the local
chord, so mid chord it is 5% of the total chord length.
I dont see anyone on Matronics talks about if they sealed the control surface hinge
gaps with tape. That will make a big difference. Tape them with Tesa fabric
tape on the bottom side of the Hinge line, inside the elevator, inside the
rudder, inside the aileron, and bottom of the flap hinge line.
Having them unsealed is like driving with the parking brake on.
On a Kitfox it is the difference of being able to make a 3-point or not with or
without sealing the elevator gap.
Jan Carlsson
JC Propeller Design
Ps. Sorry to say, I have never been onboard a KIS.
--------
www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392088#392088
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Message 3
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Subject: | Re: KIS TR-1 Airfoil |
Another=C2-option would be to make a reducer fitting and transition to a
smaller tube for the portion that goes under the horizontal.=C2- An ideal
push tube is tapered and you only need the full diameter at the center.=C2
- The fantasy push tube is tapered unidirectional boron fiber.=0A=C2-
=0ACan someone post the tube length and=C2-diameter/wall thickness=C2-a
nd the distance from the LE of the horizontal tail=C2-to the point where
the tube bolts to the elevator?=0A=C2-=0AAnother option is to switch the
whole tube=C2-to a smaller diameter steel tube.=C2- It=C2-would be th
e easiest solution,=C2-but it would add some wieght.=C2- 3-4 pounds pro
bably.=C2- =0A=C2-=0AMy forward pitch control tube is 3/4" diameter=C2
-steel on my much modified=C2-TR-1 to minimize the width of the center
console.=C2-=0A=C2-=0AScott=0A =0A=0A________________________________
=0A From: Mark Kettering <mantafs@earthlink.net>=0ATo: kis-list@matronics.c
om =0ASent: Monday, January 14, 2013 12:43 PM=0ASubject: Re: KIS-List: KIS
@earthlink.net>=0A=0A>From my calculations when I worked for Tri-R, the ele
vator push pull tube was undersized for it's length.=C2- Then talking wit
h Vance it came up that the up throw was well less than calculated due to c
ontact between the push tube and horizontal.=C2- The solution talked abou
t was to put an additional idler well aft in the fuselage and as low as pos
sible and then the most aft tube would no longer contact the horizontal.=C2
- This would solve two issues at the same time.=0A=0AI also like the idea
of increasing the length of the control arm on the elevator and changing t
he ratio on the current idler.=C2- This would reduce the load on the push
tube and increase the clearance from the tube to the horizontal.=0A=0AMark
=0A=0A-----Original Message-----=0A=0AFrom: Galin Hernandez =0A=0ASent: Jan
13, 2013 10:34 PM=0A=0ATo: kis-list@matronics.com=0A=0ASubject: Re: KIS-Li
st: KIS TR-1 Airfoil=0A=0A=0A=0AAs far as I can tell it is stock as per the
plans. Maybe that is why the VG's made a significant difference. Galin=0A
=0AOn Sun, Jan 13, 2013 at 2:12 PM, Mark Kettering <mantafs@earthlink.net>
hlink.net>=0A=0A=0A=0A=0A=0AHello Galin,=0A=0A=0A=0AIs your elevator linkag
e stock as per the plans or modified to allow for more up elevator?=C2- I
think this modification is very important and may prevent the need for VG'
s.=C2- The stock method had the control tube hit the bottom of the horizo
ntal inside the tail before a reasonable up elevator deflection limit could
be reached.=0A=0A=0A=0A=0A=0AMark=0A=0A=0A=0A=0A=0A-----Original Message--
---=0A=0A=0A=0AFrom: Galin Hernandez=0A=0A=0A=0ASent: Jan 13, 2013 10:20 AM
=0A=0A=0A=0ATo: kis-list@matronics.com=0A=0A=0A=0ASubject: Re: KIS-List: KI
S TR-1 Airfoil=0A=0A=0A=0A=0A=0A=0A=0AJan; What do you mean when you say "T
ape them with Tesa fabric tape on the bottom side of the Hinge line, inside
the elevator, inside the rudder, inside the aileron, and bottom of the fla
p hinge line." Can you provide a photo of what you mean? This sounds like a
viable option for those of us that have flying airplanes and can't re-work
the wing/tail.=0A=0A=0A=0A=0A=0A=0A=0AI used the VG's from Stolspeed.com o
n the elevator and they made a significant improvement while landing my TR-
4.=0A=0AGalinN819PR=0A=0A=0A=0AOn Fri, Jan 11, 2013 at 4:36 PM, Propellerja
n <propellerdesign@tele2.se> wrote:=0A=0A=0A=0A=0A=0A--> KIS-List message p
osted by: "Propellerjan" <propellerdesign@tele2.se>=0A=0A=0A=0A=0A=0A=0A=0A
=0A=0A=0A=0AKIS TR-1 Airfoil=0A=0A=0A=0A=0A=0A=0A=0AIn the search for infor
mation to calculate an optimum propeller for the KIS I0-240 I found a lot o
f information and thoughts about its handling especially during landing.=0A
=0A=0A=0A=0A=0A=0A=0AWhen picking an airfoil for a airplane project that is
about the last thing to do before the design is set in stone. The wing are
a is determined in respect of stall speed with flap arrangement.=0A=0A=0A
=0AWhen having MTOW, wing aspect ratio and wing area, we can calculate spee
d and lift coefficient, CL=0A=0A=0A=0A=0A=0A=0A=0AThe speed we use for this
will be where we spend most of the time, not stall speed and not top speed
, but climb and normal cruise speed. So in this range the airfoil should ha
ve the lowest drag, if it was an airliner that spend most of its time climb
ing and cruising at high altitude at low indicated speed it will be at simi
lar CL most of the time (but Mach Nr will play its roll)=0A=0A=0A=0A=0A=0A
=0A=0A=0A=0A=0A=0A=0A=0AAll aircrafts that see any production see an increa
se in installed power and weight. If this was in the design of the KIS from
start I don=99t know, but the prototype had a Limbach from start if
understand it correctly, and several hundred lbs less weight.=0A=0A=0A=0A
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AMost seem to have the I0-240B engine installe
d now and a MTOW of 1450 lb or so. And it is cruising at around 140 kts. Th
is give an lift coefficient, of around CL 0.3 at cruise, it mean that an ai
rfoil with higher camber would have been better then the current N-63A215,
where the 3:d last digit tell the designed CL So it have an airfoil designe
d for higher speeds, but no meaning to have that, no one cruise at WOT at S
L, but most cruise at 65-75% power from 2000=C2=B4 to 8000 or 12000=C2=B4
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe NACA 6x- series isn=99t
the best with today standard, rumour says that the NACA screwed up when pu
blishing these new airfoils with a faulty design that they could not take b
ack.=0A=0A=0A=0A=0A=0A=0A=0AAn Harry Riblett GA-37A315 would be a better ch
oice, it have gentler stall, and will show less drag at both cruise and cli
mb, The difference between Riblett and NACA is that the nose radii is place
d correctly on the Riblett. The Riblett will have about 7-8% higher CLmax.
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AI draw up both airfoils for evalu
ation and when aligning the portion where main and after spar will be, it i
s a different of 1 degree at the chord line. (From nose radii to trailing e
dge)=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe NACA is in Green=0A=0A=0A=0A=0A
=0A=0A=0A=0A=0A=0A=0A>From the main spar and back there is very little diff
erence in shape, meaning the lift at same angle will be about the same with
this difference in angle=0A=0A=0A=0A=0A=0A=0A=0AThe chord line is just a r
eference line that is convenient to draw and measure, but aerodynamically i
t is almost a fictive line, the important line or angle of an airfoil is th
e zero lift angle, from this line the lift is generated if it is given an a
ngle to the relative wind, think of an symmetric airfoil where the zero lif
t line and chord line is the same, and at alpha zero it will not produce an
y lift.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AAn airfoil with camber wil
l produce lift even if the chord line is at alpha zero, or slightly negativ
e, because the zero lift line will have a positive alpha to the wind.=0A=0A
=0A=0ATo make a cambered airfoil to produce zero lift, the nose have to be
lowered until the zero lift line is parallel to the wind, so an cambered ai
rfoil is said to have a zero lift angle of minus some degree depending of t
he camber, it can be -1 to -6 degree on common airfoils and camber.=0A=0A
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe NACA 63A-215 have a zer
o lift angle of -1.64 degree, and the Riblett GA-37A315 -2.14 degree.=0A=0A
=0A=0AA difference of 0.50 degree.=0A=0A=0A=0A=0A=0A=0A=0AThe lift slope Cl
alpha=C2=B4 is depending on the wing aspect ratio, for a AR of 6, the slop
e of the lift curve is CL=C2=B5 = 2Phi / 1+2/A2 = 2Phi / 1 + 2 / 6 =
4.71239 per radian=0A=0A=0A=0AOr 4.71239 / 57.3 = 0.08224 per degree=0A
=0A=0A=0A=0A=0A=0A=0AThe original wing is 3 degree up from chord line to fu
selage reference line, so if we fly it with the reference line horizontal t
he wing CL=C2- =C2- is 3 - -1.64 = 4.64 degree a 0,08224 = 0,38 CL.
=0A=0A=0A=0A=0A=0A=0A=0AThe GA-37A315 will be 1 degree less measured at the
chord line, so 2 - -2.14 = 4.14. so CL with fuselage level will be 0.34
=0A=0A=0A=0AIt means that at higher speeds the nose down angle will be 0.5
degree less.=0A=0A=0A=0A=0A=0A=0A=0ALets say we cruse at 165 MPH TAS @ 8000
=C2=B4 and 1450 Lb the CL will be 0.30 plus the fact that the wing have to
carry the down force from tail plane. Both airfoils have a negative pitch m
oment of 0.05, the Riblett just a little more then the NACA due to more cam
ber.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe load at the tail is its moment times
the wing chord and area, times dynamic pressure.=0A=0A=0A=0ADivided with ta
il length.=0A=0A=0A=0AIt will be about 84-85 lb down force at cruise if CG
is at 25% chord=0A=0A=0A=0ASo the wing then will carry 1535 lb or CL=C2-
0.32=0A=0A=0A=0A=0A=0A=0A=0AA CG further back will reduce negative lift and
then reduce induced drag. (And reversed.)=0A=0A=0A=0A1450 lb at after limi
t will reduce down force at the tail with 10 lb=0A=0A=0A=0Aat forward limit
it will ad 35 lb to a total lift the wing have to do of 1570 lb or CL 0.33
=0A=0A=0A=0A=0A=0A=0A=0AA CG to forward and the elevator will not be able t
o hold the nose up with flaps, to far back and it will be sensitive on the
stick. Then we come into:=0A=0A=0A=0A=0A=0A=0A=0ANose drop at landing, soun
ds like ground effect, when closer to ground the down wash from wing is fla
ttened out, meaning the tail will have less down force.=0A=0A=0A=0AWith a h
orizontal stab area of just a bit over 17% of the wing area, seems small, e
ven if the tail arm is long.=0A=0A=0A=0AOne reason for the elevator not be
up to the job can also be the tail incidence, 0.5 - 0.75 degree down might
help.=C2- (but hard to fix that now)=0A=0A=0A=0ASeems like, longer elevat
ors chords is a good thing, 1,75=9D longer chord move the hinge line
to 60% chord/40% elevator.=C2- (about =9Cnormal=9D)=0A=0A=0A
=0AAnd VG's, seems to help, it means something is wrong from start, to smal
l elevator or wrong incidence. Or to small H.- tail area or all three.=0A
=0A=0A=0A=0A=0A=0A=0AThe Wing =93 Fuselage fairing should be expandin
g and 10% of the chord at the trailing edge, according to Raymer, It mean i
n my eyes it should be 10% of the local chord, so mid chord it is 5% of the
total chord length.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AI don
=99t see anyone on Matronics talks about if they sealed the control surface
hinge gaps with tape. That will make a big difference. Tape them with Tesa
fabric tape on the bottom side of the Hinge line, inside the elevator, ins
ide the rudder, inside the aileron, and bottom of the flap hinge line.=0A
=0A=0A=0A=0A=0A=0A=0A=0A=0AHaving them unsealed=C2- is like driving with
the parking brake on.=0A=0A=0A=0AOn a Kitfox it is the difference of being
able to make a 3-point or not with or without sealing the elevator gap.=0A
=0A=0A=0A=0A=0A=0A=0AJan Carlsson=0A=0A=0A=0AJC Propeller Design=0A=0A=0A
=0A=0A=0A=0A=0APs. Sorry to say, I have never been onboard a KIS.=0A=0A=0A
=0A=0A=0A=0A=0A--------=0A=0A=0A=0Awww.jcpropellerdesign.com=0A=0A=0A=0A=0A
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0ARead this topic online here:
=0A=0A=0A=0A=0A=0A=0A=0Ahttp://forums.matronics.com/viewtopic.php?p=39208
8#392088=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AAttachm
ents:=0A=0A=0A=0A=0A=0A=0A=0Ahttp://forums.matronics.com//files/63a215_37a3
15_le_rad_133.jpg=0A=0A=0A=0Ahttp://forums.matronics.com//files/63a215_37a3
15_184.jpg=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=
===========0A=0A=0A=0Arget="_blank">http://www.matron
ics.com/Navigator?KIS-List=0A=0A=0A=0A============0A
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Subject: | Re: KIS TR-1 Airfoil |
The current aft elevator tube is 6061 T6, 120" long, 1.25" dia, 0.065" wall with
a margin of safety of -0.39. FYI, the forward steel tube is 4130, 51.25" long,
0.74" dia, 0.035" wall with a margin of safety of -0.35. The margin of safety
must be positive to be safe.
Steel or aluminum is a wash for weight to stiffness ratio. But for the long elevator
tube to be 1" dia steel it would need to be 0.075 wall or thicker. This
would make it over 6 times more heavy than the aluminum tube (about 10 lbs more)
and only give you 0.125" more clearance on the horizontal. Diameter really
helps for tube compression buckling resistance.
Using two tubes really reduces the load. If 2 tubes were used and they were each
60" long they could be 6061 T6, 1" dia, 0.058" wall and still have a 0.11 margin
of safety.
As Scott said, double tapered would really help.
I think the most simple solution is to increase the length of the rudder control
horn (from 4' to 5") and slightly change the idler ratio (change the long side
to 5"). Not only does this increase the clearance but it also reduces the
load on the push tube. Still not a positive margin but only about half as negative.
Mark
-----Original Message-----
From: Scott Stearns
Sent: Jan 14, 2013 4:37 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
Another option would be to make a reducer fitting and transition to a smaller tube
for the portion that goes under the horizontal. An ideal push tube is tapered
and you only need the full diameter at the center. The fantasy push tube
is tapered unidirectional boron fiber. Can someone post the tube length and diameter/wall
thickness and the distance from the LE of the horizontal tail to
the point where the tube bolts to the elevator? Another option is to switch the
whole tube to a smaller diameter steel tube. It would be the easiest solution,
but it would add some wieght. 3-4 pounds probably. My
forward pitch control tube is 3/4" diameter steel on my much modified TR-1 to
minimize the width of the center console. Scott
From: Mark Kettering <mantafs@earthlink.net>
To: kis-list@matronics.com
Sent: Monday, January 14, 2013 12:43 PM
Subject: Re: KIS-List:
KIS TR-1 Airfoil
>From my calculations when I worked for Tri-R, the elevator push pull tube was
undersized for it's length. Then talking with Vance it came up that the up throw
was well less than calculated due to contact between the push tube and horizontal.
The solution talked about was to put an additional idler well aft in
the fuselage and as low as possible and then the most aft tube would no longer
contact the horizontal. This would solve two issues at the same time.
I also like the idea of increasing the length of the control arm on the elevator
and changing the ratio on the current idler. This would reduce the load on
the push tube and increase the clearance from the tube to the horizontal.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:34 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
As far as I can tell it is stock as per the plans. Maybe that is why the VG's made
a significant difference. Galin
On Sun, Jan 13, 2013 at 2:12 PM, Mark Kettering <mantafs@earthlink.net> wrote:
Hello Galin,
Is your elevator linkage stock as per the plans or modified to allow for more up
elevator? I think this modification is very important and may prevent the need
for VG's. The stock method had the control tube hit the bottom of
the horizontal inside the tail before a reasonable up elevator deflection limit
could be reached.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:20 AM
Subject: Re: KIS-List: KIS TR-1 Airfoil
Jan; What do you mean when you say "Tape them with Tesa fabric tape on the bottom
side of the Hinge line, inside the elevator, inside the rudder, inside the
aileron, and bottom of the flap hinge line." Can you provide a photo of what you
mean? This sounds like a viable option for those of us that have flying airplanes
and can't re-work the wing/tail.
I used the VG's from Stolspeed.com on the elevator and they
made a significant improvement while landing my TR-4.
GalinN819PR
On Fri, Jan 11, 2013 at 4:36 PM, Propellerjan <propellerdesign@tele2.se> wrote:
KIS TR-1 Airfoil
In the search for information to calculate an optimum propeller for the KIS I0-240
I found a lot of information and thoughts about its handling especially during
landing.
When picking an airfoil for a airplane project that is about the last thing to
do before the design is set in stone. The wing area is determined in respect of
stall speed with flap arrangement.
When
having MTOW, wing aspect ratio and wing area, we can calculate speed and lift
coefficient, CL
The speed we use for this will be where we spend most of the time, not stall speed
and not top speed, but climb and normal cruise speed. So in this range the
airfoil should have the lowest drag, if it was an airliner that spend most of
its time climbing and cruising at high altitude at low indicated speed it will
be at similar CL most of the time (but Mach Nr will play its roll)
All aircrafts that see any production see an increase in installed power and weight.
If this was in the design of the KIS from start I dont know, but the prototype
had a Limbach from start if understand it correctly, and several hundred
lbs less weight.
Most seem to have the I0-240B engine installed now and a MTOW of 1450 lb or so.
And it is
cruising at around 140 kts. This give an lift coefficient, of around CL 0.3 at
cruise, it mean that an airfoil with higher camber would have been better then
the current N-63A215, where the 3:d last digit tell the designed CL So it have
an airfoil designed for higher speeds, but no meaning to have that, no one
cruise at WOT at SL, but most cruise at 65-75% power from 2000 to 8000 or 12000
The NACA 6x- series isnt the best with today standard, rumour says that the NACA
screwed up when publishing these new airfoils with a faulty design that they
could not take back.
An Harry Riblett GA-37A315 would be a better choice, it have gentler stall, and
will show less drag at both cruise and climb, The difference between Riblett
and NACA is that the nose radii is placed correctly on the Riblett. The Riblett
will have about 7-8% higher
CLmax.
I draw up both airfoils for evaluation and when aligning the portion where main
and after spar will be, it is a different of 1 degree at the chord line. (From
nose radii to trailing edge)
The NACA is in Green
>From the main spar and back there is very little difference in shape, meaning
the lift at same angle will be about the same with this difference in angle
The chord line is just a reference line that is convenient to draw and measure,
but aerodynamically it is almost a fictive line, the important line or angle
of an airfoil is the zero lift angle, from this line the lift is generated if
it is given an angle to the relative wind, think of an symmetric airfoil where
the zero lift line and chord line is the same, and at alpha zero it will not
produce any
lift.
An airfoil with camber will produce lift even if the chord line is at alpha zero,
or slightly negative, because the zero lift line will have a positive alpha
to the wind.
To make a cambered airfoil to produce zero lift, the nose have to be lowered until
the zero lift line is parallel to the wind, so an cambered airfoil is said
to have a zero lift angle of minus some degree depending of the camber, it can
be -1 to -6 degree on common airfoils and camber.
The NACA 63A-215 have a zero lift angle of -1.64 degree, and the Riblett GA-37A315
-2.14 degree.
A difference of 0.50 degree.
The lift slope Cl alpha is depending on the wing aspect ratio, for a AR of 6, the
slope of the lift curve is CL = 2Phi / 1+2/A2 = 2Phi / 1 + 2 / 6 = 4.71239
per radian
Or
4.71239 / 57.3 = 0.08224 per degree
The original wing is 3 degree up from chord line to fuselage reference line, so
if we fly it with the reference line horizontal the wing CL is 3 - -1.64 =
4.64 degree a 0,08224 = 0,38 CL.
The GA-37A315 will be 1 degree less measured at the chord line, so 2 - -2.14 =
4.14. so CL with fuselage level will be 0.34
It means that at higher speeds the nose down angle will be 0.5 degree less.
Lets say we cruse at 165 MPH TAS @ 8000 and 1450 Lb the CL will be 0.30 plus the
fact that the wing have to carry the down force from tail plane. Both airfoils
have a negative pitch moment of 0.05, the Riblett just a little more then the
NACA due to more camber.
The load at the tail is its moment times the wing chord and area, times dynamic
pressure.
Divided with
tail length.
It will be about 84-85 lb down force at cruise if CG is at 25% chord
So the wing then will carry 1535 lb or CL 0.32
A CG further back will reduce negative lift and then reduce induced drag. (And
reversed.)
1450 lb at after limit will reduce down force at the tail with 10 lb
at forward limit it will ad 35 lb to a total lift the wing have to do of 1570 lb
or CL 0.33
A CG to forward and the elevator will not be able to hold the nose up with flaps,
to far back and it will be sensitive on the stick. Then we come into:
Nose drop at landing, sounds like ground effect, when closer to ground the down
wash from wing is flattened out, meaning the tail will have less down force.
With a horizontal stab area of just a bit over 17% of the wing area, seems small,
even if the tail arm
is long.
One reason for the elevator not be up to the job can also be the tail incidence,
0.5 - 0.75 degree down might help. (but hard to fix that now)
Seems like, longer elevators chords is a good thing, 1,75 longer chord move the
hinge line to 60% chord/40% elevator. (about normal)
And VG's, seems to help, it means something is wrong from start, to small elevator
or wrong incidence. Or to small H.- tail area or all three.
The Wing Fuselage fairing should be expanding and 10% of the chord at the trailing
edge, according to Raymer, It mean in my eyes it should be 10% of the local
chord, so mid chord it is 5% of the total chord length.
I dont see anyone on Matronics talks about if they sealed the control surface hinge
gaps with tape. That will make a big difference. Tape them with Tesa fabric
tape
on the bottom side of the Hinge line, inside the elevator, inside the rudder,
inside the aileron, and bottom of the flap hinge line.
Having them unsealed is like driving with the parking brake on.
On a Kitfox it is the difference of being able to make a 3-point or not with or
without sealing the elevator gap.
Jan Carlsson
JC Propeller Design
Ps. Sorry to say, I have never been onboard a KIS.
--------
www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392088#392088
Attachments:
http://forums.matronics.com//files/63a215_37a315_le_rad_133.jpg
http://forums.matronics.com//files/63a215_37a315_184.jpg
==========
rget="_blank">http://www.matronics.com/Navigator?KIS-List
==========
http://forums.matronics.com/
==========
le, List
Admin.
="_blank">http://www.matronics.com/contribution
==========
==========
rget="_blank">http://www.matronics.com/Navigator?KIS-List
==========
http://forums.matronics.com/
==========
le, List Admin.
="_blank">http://www.matronics.com/contribution
==========
<br use="" the="" matronics="" list="" ->="" http://www.=====================
Message 5
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Subject: | Re: KIS TR-1 Airfoil |
This is Jesse,
I built and used the materials that came with the kit. I achieved the
degrees of up elevator called for in the prints. How close the down arm f
rom
the elevator comes to hitting something I don't know now. "I'm surprised
these problems didn't surface before now. Maybe they did and I missed the
m,
which is it? I'm assuming we're still talking about the TR-1.
In a message dated 1/14/2013 6:49:26 P.M. Mountain Standard Time,
mantafs@earthlink.net writes:
--> KIS-List message posted by: Mark Kettering <mantafs@earthlink.net>
The current aft elevator tube is 6061 T6, 120" long, 1.25" dia, 0.065"
wall with a margin of safety of -0.39. FYI, the forward steel tube is 413
0,
51.25" long, 0.74" dia, 0.035" wall with a margin of safety of -0.35. The
margin of safety must be positive to be safe.
Steel or aluminum is a wash for weight to stiffness ratio. But for the
long elevator tube to be 1" dia steel it would need to be 0.075 wall or
thicker. This would make it over 6 times more heavy than the aluminum tub
e
(about 10 lbs more) and only give you 0.125" more clearance on the horizon
tal.
Diameter really helps for tube compression buckling resistance.
Using two tubes really reduces the load. If 2 tubes were used and they
were each 60" long they could be 6061 T6, 1" dia, 0.058" wall and still ha
ve
a 0.11 margin of safety.
As Scott said, double tapered would really help.
I think the most simple solution is to increase the length of the rudder
control horn (from 4' to 5") and slightly change the idler ratio (change t
he
long side to 5"). Not only does this increase the clearance but it also
reduces the load on the push tube. Still not a positive margin but only
about half as negative.
Mark
-----Original Message-----
From: Scott Stearns
Sent: Jan 14, 2013 4:37 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
Another option would be to make a reducer fitting and transition to a
smaller tube for the portion that goes under the horizontal. An ideal pus
h
tube is tapered and you only need the full diameter at the center. The
fantasy push tube is tapered unidirectional boron fiber. Can someone post
the
tube length and diameter/wall thickness and the distance from the LE of th
e
horizontal tail to the point where the tube bolts to the elevator? Another
option is to switch the whole tube to a smaller diameter steel tube. It
would be the easiest solution, but it would add some wieght. 3-4 pounds
probably. My
forward pitch control tube is 3/4" diameter steel on my much modified TR-1
to minimize the width of the center console. Scott
From: Mark Kettering <mantafs@earthlink.net>
Sent: Monday, January 14, 2013 12:43 PM
Subject: Re: KIS-List:
KIS TR-1 Airfoil
--> KIS-List message posted by: Mark Kettering <mantafs@earthlink.net>
>From my calculations when I worked for Tri-R, the elevator push pull tube
was undersized for it's length. Then talking with Vance it came up that
the up throw was well less than calculated due to contact between the push
tube and horizontal. The solution talked about was to put an additional
idler well aft in the fuselage and as low as possible and then the most af
t
tube would no longer contact the horizontal. This would solve two issues
at
the same time.
I also like the idea of increasing the length of the control arm on the
elevator and changing the ratio on the current idler. This would reduce t
he
load on the push tube and increase the clearance from the tube to the
horizontal.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:34 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
As far as I can tell it is stock as per the plans. Maybe that is why the
VG's made a significant difference. Galin
On Sun, Jan 13, 2013 at 2:12 PM, Mark Kettering <mantafs@earthlink.net>
wrote:
Hello Galin,
Is your elevator linkage stock as per the plans or modified to allow for
more up elevator? I think this modification is very important and may
prevent the need for VG's. The stock method had the control tube hit the
bottom
of
the horizontal inside the tail before a reasonable up elevator deflection
limit could be reached.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:20 AM
Subject: Re: KIS-List: KIS TR-1 Airfoil
Jan; What do you mean when you say "Tape them with Tesa fabric tape on the
bottom side of the Hinge line, inside the elevator, inside the rudder,
inside the aileron, and bottom of the flap hinge line." Can you provide a
photo of what you mean? This sounds like a viable option for those of us t
hat
have flying airplanes and can't re-work the wing/tail.
I used the VG's from Stolspeed.com on the elevator and they
made a significant improvement while landing my TR-4.
GalinN819PR
On Fri, Jan 11, 2013 at 4:36 PM, Propellerjan <propellerdesign@tele2.se>
wrote:
KIS TR-1 Airfoil
In the search for information to calculate an optimum propeller for the
KIS I0-240 I found a lot of information and thoughts about its handling
especially during landing.
When picking an airfoil for a airplane project that is about the last
thing to do before the design is set in stone. The wing area is determined
in
respect of stall speed with flap arrangement.
When
having MTOW, wing aspect ratio and wing area, we can calculate speed and
lift coefficient, CL
The speed we use for this will be where we spend most of the time, not
stall speed and not top speed, but climb and normal cruise speed. So in th
is
range the airfoil should have the lowest drag, if it was an airliner that
spend most of its time climbing and cruising at high altitude at low
indicated speed it will be at similar CL most of the time (but Mach Nr wil
l play
its roll)
All aircrafts that see any production see an increase in installed power
and weight. If this was in the design of the KIS from start I don=99
t know,
but the prototype had a Limbach from start if understand it correctly, and
several hundred lbs less weight.
Most seem to have the I0-240B engine installed now and a MTOW of 1450 lb
or so. And it is
cruising at around 140 kts. This give an lift coefficient, of around CL
0.3 at cruise, it mean that an airfoil with higher camber would have been
better then the current N-63A215, where the 3:d last digit tell the designe
d
CL So it have an airfoil designed for higher speeds, but no meaning to have
that, no one cruise at WOT at SL, but most cruise at 65-75% power from 2000
=C2=B4
to 8000 or 12000=C2=B4
The NACA 6x- series isn=99t the best with today standard, rumour say
s that
the NACA screwed up when publishing these new airfoils with a faulty desig
n
that they could not take back.
An Harry Riblett GA-37A315 would be a better choice, it have gentler
stall, and will show less drag at both cruise and climb, The difference be
tween
Riblett and NACA is that the nose radii is placed correctly on the Riblett
.
The Riblett will have about 7-8% higher
CLmax.
I draw up both airfoils for evaluation and when aligning the portion where
main and after spar will be, it is a different of 1 degree at the chord
line. (From nose radii to trailing edge)
The NACA is in Green
>From the main spar and back there is very little difference in shape,
meaning the lift at same angle will be about the same with this difference
in
angle
The chord line is just a reference line that is convenient to draw and
measure, but aerodynamically it is almost a fictive line, the important li
ne
or angle of an airfoil is the zero lift angle, from this line the lift is
generated if it is given an angle to the relative wind, think of an symmet
ric
airfoil where the zero lift line and chord line is the same, and at alpha
zero it will not produce any
lift.
An airfoil with camber will produce lift even if the chord line is at
alpha zero, or slightly negative, because the zero lift line will have a
positive alpha to the wind.
To make a cambered airfoil to produce zero lift, the nose have to be
lowered until the zero lift line is parallel to the wind, so an cambered a
irfoil
is said to have a zero lift angle of minus some degree depending of the
camber, it can be -1 to -6 degree on common airfoils and camber.
The NACA 63A-215 have a zero lift angle of -1.64 degree, and the Riblett
GA-37A315 -2.14 degree.
A difference of 0.50 degree.
The lift slope Cl alpha=C2=B4 is depending on the wing aspect ratio, for a
AR
of 6, the slope of the lift curve is CL=C2=B5 = 2Phi / 1+2/A2 = 2Phi /
1 + 2 / 6
= 4.71239 per radian
Or
4.71239 / 57.3 = 0.08224 per degree
The original wing is 3 degree up from chord line to fuselage reference
line, so if we fly it with the reference line horizontal the wing CL is
3 -
-1.64 = 4.64 degree a 0,08224 = 0,38 CL.
The GA-37A315 will be 1 degree less measured at the chord line, so 2 -
-2.14 = 4.14. so CL with fuselage level will be 0.34
It means that at higher speeds the nose down angle will be 0.5 degree less
.
Lets say we cruse at 165 MPH TAS @ 8000=C2=B4 and 1450 Lb the CL will be 0
.30
plus the fact that the wing have to carry the down force from tail plane.
Both airfoils have a negative pitch moment of 0.05, the Riblett just a lit
tle
more then the NACA due to more camber.
The load at the tail is its moment times the wing chord and area, times
dynamic pressure.
Divided with
tail length.
It will be about 84-85 lb down force at cruise if CG is at 25% chord
So the wing then will carry 1535 lb or CL 0.32
A CG further back will reduce negative lift and then reduce induced drag.
(And reversed.)
1450 lb at after limit will reduce down force at the tail with 10 lb
at forward limit it will ad 35 lb to a total lift the wing have to do of
1570 lb or CL 0.33
A CG to forward and the elevator will not be able to hold the nose up with
flaps, to far back and it will be sensitive on the stick. Then we come
into:
Nose drop at landing, sounds like ground effect, when closer to ground the
down wash from wing is flattened out, meaning the tail will have less down
force.
With a horizontal stab area of just a bit over 17% of the wing area, seems
small, even if the tail arm
is long.
One reason for the elevator not be up to the job can also be the tail
incidence, 0.5 - 0.75 degree down might help. (but hard to fix that now)
Seems like, longer elevators chords is a good thing, 1,75=9D longer
chord
move the hinge line to 60% chord/40% elevator. (about =9Cnormal
=9D)
And VG's, seems to help, it means something is wrong from start, to small
elevator or wrong incidence. Or to small H.- tail area or all three.
The Wing =93 Fuselage fairing should be expanding and 10% of the cho
rd at
the trailing edge, according to Raymer, It mean in my eyes it should be 10
%
of the local chord, so mid chord it is 5% of the total chord length.
I don=99t see anyone on Matronics talks about if they sealed the con
trol
surface hinge gaps with tape. That will make a big difference. Tape them w
ith
Tesa fabric tape
on the bottom side of the Hinge line, inside the elevator, inside the
rudder, inside the aileron, and bottom of the flap hinge line.
Having them unsealed is like driving with the parking brake on.
On a Kitfox it is the difference of being able to make a 3-point or not
with or without sealing the elevator gap.
Jan Carlsson
JC Propeller Design
Ps. Sorry to say, I have never been onboard a KIS.
--------
www.jcpropellerdesign.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=392088#392088
Attachments:
http://forums.matronics.com//files/63a215_37a315_le_rad_133.jpg
http://forums.matronics.com//files/63a215_37a315_184.jpg
rget="_blank">http://www.matronics.com/Navigator?KIS-List
http://forums.matronics.com/
le, List
Admin.
="_blank">http://www.matronics.com/contribution
rget="_blank">http://www.matronics.com/Navigator?KIS-List
http://forums.matronics.com/
le, List Admin.
="_blank">http://www.matronics.com/contribution
="" http://www.===================
==
Message 6
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|
Subject: | Re: KIS TR-1 Airfoil |
If a 60" long 1" diameter tube will take the load then just reduce the last
30" of the tube to 1" diameter.=C2- =0A=C2-=0AWe are talking about the
Cruiser right?=0A=C2-=0AScott=0A =0A=0A________________________________
=0A From: Mark Kettering <mantafs@earthlink.net>=0ATo: kis-list@matronics.c
om =0ASent: Monday, January 14, 2013 5:49 PM=0ASubject: Re: KIS-List: KIS T
earthlink.net>=0A=0AThe current aft elevator tube is 6061 T6, 120" long, 1.
25" dia, 0.065" wall with a margin of safety of -0.39.=C2- FYI, the forwa
rd steel tube is 4130, 51.25" long, 0.74" dia, 0.035" wall with a margin of
safety of -0.35.=C2- The margin of safety must be positive to be safe.
=0A=0ASteel or aluminum is a wash for weight to stiffness ratio.=C2- But
for the long elevator tube to be 1" dia steel it would need to be 0.075 wal
l or thicker.=C2- This would make it over 6 times more heavy than the alu
minum tube (about 10 lbs more) and only give you 0.125" more clearance on t
he horizontal.=C2- Diameter really helps for tube compression buckling re
sistance.=0A=0AUsing two tubes really reduces the load.=C2- If 2 tubes we
re used and they were each 60" long they could be 6061 T6, 1" dia, 0.058" w
all and still have a 0.11 margin of safety.=0A=0AAs Scott said, double tape
red would really help.=0A=0AI think the most simple solution is to increase
the length of the rudder control horn (from 4' to 5") and slightly change
the idler ratio (change the long side to 5").=C2- Not only does this incr
ease the clearance but it also reduces the load on the push tube.=C2- Sti
ll not a positive margin but only about half as negative.=0A=0AMark=0A=0A--
---Original Message-----=0A=0AFrom: Scott Stearns =0A=0ASent: Jan 14, 2013
4:37 PM=0A=0ATo: "kis-list@matronics.com" =0A=0ASubject: Re: KIS-List: KIS
TR-1 Airfoil=0A=0A=0A=0AAnother option would be to make a reducer fitting a
nd transition to a smaller tube for the portion that goes under the horizon
tal.=C2- An ideal push tube is tapered and you only need the full diamete
r at the center.=C2- The fantasy push tube is tapered unidirectional boro
n fiber. Can someone post the tube length and diameter/wall thickness and t
he distance from the LE of the horizontal tail to the point where the tube
bolts to the elevator? Another option is to switch the whole tube to a smal
ler diameter steel tube.=C2- It would be the easiest solution, but it wou
ld add some wieght.=C2- 3-4 pounds probably.=C2- My=0Aforward pitch co
ntrol tube is 3/4" diameter steel on my much modified TR-1 to minimize the
width of the center console.=C2- Scott=0A=C2- =C2- =C2- =C2- From
: Mark Kettering <mantafs@earthlink.net>=0ATo: kis-list@matronics.com =0ASe
nt: Monday, January 14, 2013 12:43 PM=0ASubject: Re: KIS-List:=0AKIS TR-1 A
fs@earthlink.net>=0A=0A>From my calculations when I worked for Tri-R, the e
levator push pull tube was undersized for it's length.=C2- Then talking w
ith Vance it came up that the up throw was well less than calculated due to
contact between the push tube and horizontal.=C2- The solution talked ab
out was to put an additional idler well aft in the fuselage and as low as p
ossible and then the most aft tube would no longer contact the horizontal.
=C2- This would solve two issues at the same time.=0A=0AI also like the i
dea of increasing the length of the control arm on the elevator and changin
g the ratio on the current idler.=C2- This would reduce the load on the p
ush tube and increase the clearance from the tube to the horizontal.=0A=0AM
ark=0A=0A-----Original Message-----=0A=0AFrom: Galin Hernandez=0A=0A=0ASent
: Jan 13, 2013 10:34 PM=0A=0ATo: kis-list@matronics.com=0A=0ASubject: Re: K
IS-List: KIS TR-1 Airfoil=0A=0A=0A=0AAs far as I can tell it is stock as pe
r the plans. Maybe that is why the VG's made a significant difference. Gali
n=0A=0AOn Sun, Jan 13, 2013 at 2:12 PM, Mark Kettering <mantafs@earthlink.n
earthlink.net>=0A=0A=0A=0A=0A=0AHello Galin,=0A=0A=0A=0AIs your elevator li
nkage stock as per the plans or modified to allow for more up elevator?=C2
- I think this modification is very important and may prevent the need fo
r VG's.=C2- The stock method had the control tube hit the bottom of=0Athe
horizontal inside the tail before a reasonable up elevator deflection limi
t could be reached.=0A=0A=0A=0A=0A=0AMark=0A=0A=0A=0A=0A=0A-----Original Me
ssage-----=0A=0A=0A=0AFrom: Galin Hernandez=0A=0A=0A=0ASent: Jan 13, 2013 1
0:20 AM=0A=0A=0A=0ATo: kis-list@matronics.com=0A=0A=0A=0ASubject: Re: KIS-L
ist: KIS TR-1 Airfoil=0A=0A=0A=0A=0A=0A=0A=0AJan; What do you mean when you
say "Tape them with Tesa fabric tape on the bottom side of the Hinge line,
inside the elevator, inside the rudder, inside the aileron, and bottom of
the flap hinge line." Can you provide a photo of what you mean? This sounds
like a viable option for those of us that have flying airplanes and can't
re-work the wing/tail.=0A=0A=0A=0A=0A=0A=0A=0AI used the VG's from Stolspee
d.com on the elevator and they=0Amade a significant improvement while landi
ng my TR-4.=0A=0AGalinN819PR=0A=0A=0A=0AOn Fri, Jan 11, 2013 at 4:36 PM, Pr
opellerjan <propellerdesign@tele2.se> wrote:=0A=0A=0A=0A=0A=0A--> KIS-List
message posted by: "Propellerjan" <propellerdesign@tele2.se>=0A=0A=0A=0A=0A
=0A=0A=0A=0A=0A=0A=0AKIS TR-1 Airfoil=0A=0A=0A=0A=0A=0A=0A=0AIn the search
for information to calculate an optimum propeller for the KIS I0-240 I foun
d a lot of information and thoughts about its handling especially during la
nding.=0A=0A=0A=0A=0A=0A=0A=0AWhen picking an airfoil for a airplane projec
t that is about the last thing to do before the design is set in stone. The
wing area is determined in respect of stall speed with flap arrangement.
=0A=0A=0A=0AWhen=0Ahaving MTOW, wing aspect ratio and wing area, we can cal
culate speed and lift coefficient, CL=0A=0A=0A=0A=0A=0A=0A=0AThe speed we u
se for this will be where we spend most of the time, not stall speed and no
t top speed, but climb and normal cruise speed. So in this range the airfoi
l should have the lowest drag, if it was an airliner that spend most of its
time climbing and cruising at high altitude at low indicated speed it will
be at similar CL most of the time (but Mach Nr will play its roll)=0A=0A
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AAll aircrafts that see any production s
ee an increase in installed power and weight. If this was in the design of
the KIS from start I don=99t know, but the prototype had a Limbach fr
om start if understand it correctly, and several hundred lbs less weight.
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AMost seem to have the I0-240B eng
ine installed now and a MTOW of 1450 lb or so. And it is=0Acruising at arou
nd 140 kts. This give an lift coefficient, of around CL 0.3 at cruise, it m
ean that an airfoil with higher camber would have been better then the curr
ent N-63A215, where the 3:d last digit tell the designed CL So it have an a
irfoil designed for higher speeds, but no meaning to have that, no one crui
se at WOT at SL, but most cruise at 65-75% power from 2000=C2=B4 to 8000 or
12000=C2=B4=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe NACA 6x- series i
sn=99t the best with today standard, rumour says that the NACA screwe
d up when publishing these new airfoils with a faulty design that they coul
d not take back.=0A=0A=0A=0A=0A=0A=0A=0AAn Harry Riblett GA-37A315 would be
a better choice, it have gentler stall, and will show less drag at both cr
uise and climb, The difference between Riblett and NACA is that the nose ra
dii is placed correctly on the Riblett. The Riblett will have about 7-8% hi
gher=0ACLmax.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AI draw up both airfo
ils for evaluation and when aligning the portion where main and after spar
will be, it is a different of 1 degree at the chord line. (From nose radii
to trailing edge)=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe NACA is in Green
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A>From the main spar and back there is v
ery little difference in shape, meaning the lift at same angle will be abou
t the same with this difference in angle=0A=0A=0A=0A=0A=0A=0A=0AThe chord l
ine is just a reference line that is convenient to draw and measure, but ae
rodynamically it is almost a fictive line, the important line or angle of a
n airfoil is the zero lift angle, from this line the lift is generated if i
t is given an angle to the relative wind, think of an symmetric airfoil whe
re the zero lift line and chord line is the same, and at alpha zero it will
not produce any=0Alift.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AAn airfoi
l with camber will produce lift even if the chord line is at alpha zero, or
slightly negative, because the zero lift line will have a positive alpha t
o the wind.=0A=0A=0A=0ATo make a cambered airfoil to produce zero lift, the
nose have to be lowered until the zero lift line is parallel to the wind,
so an cambered airfoil is said to have a zero lift angle of minus some degr
ee depending of the camber, it can be -1 to -6 degree on common airfoils an
d camber.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe NACA 63A
-215 have a zero lift angle of -1.64 degree, and the Riblett GA-37A315 -2.1
4 degree.=0A=0A=0A=0AA difference of 0.50 degree.=0A=0A=0A=0A=0A=0A=0A=0ATh
e lift slope Cl alpha=C2=B4 is depending on the wing aspect ratio, for a AR
of 6, the slope of the lift curve is CL=C2=B5 = 2Phi / 1+2/A2 = 2Phi /
1 + 2 / 6 = 4.71239 per radian=0A=0A=0A=0AOr=0A4.71239 / 57.3 = 0.0822
4 per degree=0A=0A=0A=0A=0A=0A=0A=0AThe original wing is 3 degree up from c
hord line to fuselage reference line, so if we fly it with the reference li
ne horizontal the wing CL=C2- =C2- is 3 - -1.64 = 4.64 degree a 0,082
24 = 0,38 CL.=0A=0A=0A=0A=0A=0A=0A=0AThe GA-37A315 will be 1 degree less
measured at the chord line, so 2 - -2.14 = 4.14. so CL with fuselage leve
l will be 0.34=0A=0A=0A=0AIt means that at higher speeds the nose down angl
e will be 0.5 degree less.=0A=0A=0A=0A=0A=0A=0A=0ALets say we cruse at 165
MPH TAS @ 8000=C2=B4 and 1450 Lb the CL will be 0.30 plus the fact that the
wing have to carry the down force from tail plane. Both airfoils have a ne
gative pitch moment of 0.05, the Riblett just a little more then the NACA d
ue to more camber.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AThe load at the tail is its
moment times the wing chord and area, times dynamic pressure.=0A=0A=0A=0AD
ivided with=0Atail length.=0A=0A=0A=0AIt will be about 84-85 lb down force
at cruise if CG is at 25% chord=0A=0A=0A=0ASo the wing then will carry 1535
lb or CL=C2- 0.32=0A=0A=0A=0A=0A=0A=0A=0AA CG further back will reduce n
egative lift and then reduce induced drag. (And reversed.)=0A=0A=0A=0A1450
lb at after limit will reduce down force at the tail with 10 lb=0A=0A=0A=0A
at forward limit it will ad 35 lb to a total lift the wing have to do of 15
70 lb or CL 0.33=0A=0A=0A=0A=0A=0A=0A=0AA CG to forward and the elevator wi
ll not be able to hold the nose up with flaps, to far back and it will be s
ensitive on the stick. Then we come into:=0A=0A=0A=0A=0A=0A=0A=0ANose drop
at landing, sounds like ground effect, when closer to ground the down wash
from wing is flattened out, meaning the tail will have less down force.=0A
=0A=0A=0AWith a horizontal stab area of just a bit over 17% of the wing are
a, seems small, even if the tail arm=0Ais long.=0A=0A=0A=0AOne reason for t
he elevator not be up to the job can also be the tail incidence, 0.5 - 0.75
degree down might help.=C2- (but hard to fix that now)=0A=0A=0A=0ASeems
like, longer elevators chords is a good thing, 1,75=9D longer chord m
ove the hinge line to 60% chord/40% elevator.=C2- (about =9Cnormal
=9D)=0A=0A=0A=0AAnd VG's, seems to help, it means something is wrong
from start, to small elevator or wrong incidence. Or to small H.- tail area
or all three.=0A=0A=0A=0A=0A=0A=0A=0AThe Wing =93 Fuselage fairing s
hould be expanding and 10% of the chord at the trailing edge, according to
Raymer, It mean in my eyes it should be 10% of the local chord, so mid chor
d it is 5% of the total chord length.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A
=0A=0AI don=99t see anyone on Matronics talks about if they sealed th
e control surface hinge gaps with tape. That will make a big difference. Ta
pe them with Tesa fabric tape=0Aon the bottom side of the Hinge line, insid
e the elevator, inside the rudder, inside the aileron, and bottom of the fl
ap hinge line.=0A=0A=0A=0A=0A=0A=0A=0A=0A=0AHaving them unsealed=C2- is l
ike driving with the parking brake on.=0A=0A=0A=0AOn a Kitfox it is the dif
ference of being able to make a 3-point or not with or without sealing the
elevator gap.=0A=0A=0A=0A=0A=0A=0A=0AJan Carlsson=0A=0A=0A=0AJC Propeller D
esign=0A=0A=0A=0A=0A=0A=0A=0APs. Sorry to say, I have never been onboard a
KIS.=0A=0A=0A=0A=0A=0A=0A=0A--------=0A=0A=0A=0Awww.jcpropellerdesign.com
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0ARead this topic
online here:=0A=0A=0A=0A=0A=0A=0A=0Ahttp://forums.matronics.com/viewtopic.
php?p=392088#392088=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A
=0A=0AAttachments:=0A=0A=0A=0A=0A=0A=0A=0Ahttp://forums.matronics.com//file
s/63a215_37a315_le_rad_133.jpg=0A=0A=0A=0Ahttp://forums.matronics.com//file
s/63a215_37a315_184.jpg=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A
=0A=0A=0A============0A=0A=0A=0Arget="_blank">http:
//www.matronics.com/Navigator?KIS-List=0A=0A=0A=0A========
====0A=0A=0A=0Ahttp://forums.matronics.com/=0A=0A=0A=0A====
========0A=0A=0A=0Ale, List=0AAdmin.=0A=0A=0A=0A="_blank">h
ttp://www.matronics.com/contribution=0A=0A=0A=0A=========
===0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A
=0A=0A=0A=0A=0A=0A=0A============0A=0Arget="_blank"
>http://www.matronics.com/Navigator?KIS-List=0A=0A========
====0A=0Ahttp://forums.matronics.com/=0A=0A========
====0A=0Ale, List Admin.=0A=0A="_blank">http://www.matronics.com/co
ntribution=0A=0A============0A=0A=0A=0A=0A<br use="
" the="" matronics="" list="" ->="" http://www.======
================/=0A=0A=0A=0A=0A=0A=C2-
- =C2- =C2- =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Adm
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Subject: | Re: KIS TR-1 Airfoil |
Hi Jesse,=0A=C2-=0AMark's numbers are based on part 23 certified airplane
loads.=C2- Which means a 100 pound push/pull on the control stick.=C2-
I doubt I have or will ever pull more than 20 pounds on my stick.=C2-=C2
- If I were designing an airplane I would use part 23 control loads, but
it probably isn't anything to lose sleep over in our kisi.=0A=C2-=0AScott
=0A =0A=0A________________________________=0A From: "Flyinisfun@aol.com" <F
lyinisfun@aol.com>=0ATo: kis-list@matronics.com =0ASent: Monday, January 14
, 2013 6:08 PM=0ASubject: Re: KIS-List: KIS TR-1 Airfoil=0A =0A=0A =0AThis
is Jesse, =0AI built and used the materials that came with the kit.=C2-
I achieved the =0Adegrees of up elevator called for=C2-in the prints.=C2
- How close the down =0Aarm from the elevator comes to hitting something
I don't know now.=C2-"I'm =0Asurprised these problems didn't surface befo
re now.=C2- Maybe they did and I =0Amissed them, which is it?=C2- I'm a
ssuming we're still talking about the =0ATR-1. =0A=0A=0A=0AIn a message dat
ed 1/14/2013 6:49:26 P.M. Mountain Standard Time, =0Amantafs@earthlink.net
writes: =0A--> KIS-List message posted by: Mark Kettering <mantafs@earthl
ink.net>=0A>=0A>The current aft elevator tube is 6061 T6, =0A 120" long, 1
.25" dia, 0.065" wall with a margin of safety of -0.39.=C2- FYI, =0A the
forward steel tube is 4130, 51.25" long, 0.74" dia, 0.035" wall with a =0A
margin of safety of -0.35.=C2- The margin of safety must be positive to
be =0A safe.=0A>=0A>Steel or aluminum is a wash for weight to stiffness r
atio.=C2- =0A But for the long elevator tube to be 1" dia steel it would
need to be 0.075 =0A wall or thicker.=C2- This would make it over 6 tim
es more heavy than the =0A aluminum tube (about 10 lbs more) and only give
you 0.125" more clearance on =0A the horizontal.=C2- Diameter really he
lps for tube compression buckling =0A resistance.=0A>=0A>Using two tubes r
eally reduces the load.=C2- If 2 tubes =0A were used and they were each
60" long they could be 6061 T6, 1" dia, 0.058" =0A wall and still have a 0
.11 margin of safety.=0A>=0A>As Scott said, double =0A tapered would reall
y help.=0A>=0A>I think the most simple solution is to =0A increase the len
gth of the rudder control horn (from 4' to 5") and slightly =0A change the
idler ratio (change the long side to 5").=C2- Not only does this =0A in
crease the clearance but it also reduces the load on the push tube.=C2-
=0A Still not a positive margin but only about half as =0A negative.=0A>
=0A>Mark=0A>=0A>-----Original Message-----=0A>=0A>From: Scott =0A Stearns
=0A>=0A>Sent: Jan 14, 2013 4:37 PM=0A>=0A>To: "kis-list@matronics.com" =0A>
=0A>Subject: Re: KIS-List: KIS TR-1 Airfoil=0A>=0A>=0A>=0A>Another option
=0A would be to make a reducer fitting and transition to a smaller tube fo
r the =0A portion that goes under the horizontal.=C2- An ideal push tube
is tapered =0A and you only need the full diameter at the center.=C2- T
he fantasy push tube =0A is tapered unidirectional boron fiber. Can someon
e post the tube length and =0A diameter/wall thickness and the distance fr
om the LE of the horizontal tail to =0A the point where the tube bolts to
the elevator? Another option is to switch =0A the whole tube to a smaller
diameter steel tube.=C2- It would be the easiest =0A solution, but it wo
uld add some wieght.=C2- 3-4 pounds probably.=C2-=C2- =0A My=0A>forw
ard pitch control tube is 3/4" diameter steel on my much modified =0A TR-1
to minimize the width of the center console.=C2- Scott=0A>=C2- =C2-
=0A =C2- =C2- From: Mark Kettering <mantafs@earthlink.net>=0A>To: =0A
kis-list@matronics.com =0A>Sent: Monday, January 14, 2013 12:43 PM=0A>Subj
ect: =0A Re: KIS-List:=0A>KIS TR-1 Airfoil=0A>=C2-=C2- =0A>=0A>--> KIS
-List =0A message posted by: Mark Kettering =0A <mantafs@earthlink.net>
=0A>=0A>>From my calculations when I worked =0A for Tri-R, the elevator pu
sh pull tube was undersized for it's length.=C2- =0A Then talking with V
ance it came up that the up throw was well less than =0A calculated due to
contact between the push tube and horizontal.=C2- The =0A solution talk
ed about was to put an additional idler well aft in the fuselage =0A and a
s low as possible and then the most aft tube would no longer contact the
=0A horizontal.=C2- This would solve two issues at the same time.=0A>=0A
>I also =0A like the idea of increasing the length of the control arm on t
he elevator and =0A changing the ratio on the current idler.=C2- This wo
uld reduce the load on =0A the push tube and increase the clearance from t
he tube to the =0A horizontal.=0A>=0A>Mark=0A>=0A>-----Original Message---
--=0A>=0A>From: Galin =0A Hernandez=0A>=0A>=0A>Sent: Jan 13, 2013 10:34 PM
=0A>=0A>To: =0A kis-list@matronics.com=0A>=0A>Subject: Re: KIS-List: KIS T
R-1 =0A Airfoil=0A>=0A>=0A>=0A>As far as I can tell it is stock as per the
plans. =0A Maybe that is why the VG's made a significant difference. Gali
n=0A>=0A>On Sun, =0A Jan 13, 2013 at 2:12 PM, Mark Kettering <mantafs@eart
ering =0A <mantafs@earthlink.net>=0A>=0A>=0A>=0A>=0A>=0A>Hello =0A Galin,
=0A>=0A>=0A>=0A>Is your elevator linkage stock as per the plans or =0A mod
ified to allow for more up elevator?=C2- I think this modification is =0A
very important and may prevent the need for VG's.=C2- The stock method
had =0A the control tube hit the bottom of=0A>the horizontal inside the ta
il before a =0A reasonable up elevator deflection limit could be =0A reac
hed.=0A>=0A>=0A>=0A>=0A>=0A>Mark=0A>=0A>=0A>=0A>=0A>=0A>-----Original =0A
Message-----=0A>=0A>=0A>=0A>From: Galin Hernandez=0A>=0A>=0A>=0A>Sent: Jan
13, =0A 2013 10:20 AM=0A>=0A>=0A>=0A>To: =0A kis-list@matronics.com=0A>
=0A>=0A>=0A>Subject: Re: KIS-List: KIS TR-1 =0A Airfoil=0A>=0A>=0A>=0A>=0A
>=0A>=0A>=0A>Jan; What do you mean when you say =0A "Tape them with Tesa f
abric tape on the bottom side of the Hinge line, inside =0A the elevator,
inside the rudder, inside the aileron, and bottom of the flap =0A hinge li
ne." Can you provide a photo of what you mean? This sounds like a =0A viab
le option for those of us that have flying airplanes and can't re-work the
=0A wing/tail.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>I used the VG's from Stolspe
ed.com =0A on the elevator and they=0A>made a significant improvement whil
e landing my =0A TR-4.=0A>=0A>GalinN819PR=0A>=0A>=0A>=0A>On Fri, Jan 11, 2
013 at 4:36 PM, =0A Propellerjan <propellerdesign@tele2.se> =0A wrote:=0A
=0A <propellerdesign@tele2.se>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>
=0A>KIS =0A TR-1 Airfoil=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>In the search for
information to =0A calculate an optimum propeller for the KIS I0-240 I fou
nd a lot of information =0A and thoughts about its handling especially dur
ing =0A landing.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>When picking an airfoil fo
r a airplane =0A project that is about the last thing to do before the des
ign is set in stone. =0A The wing area is determined in respect of stall s
peed with flap =0A arrangement.=0A>=0A>=0A>=0A>When=0A>having MTOW, wing a
spect ratio and wing =0A area, we can calculate speed and lift coefficient
, =0A CL=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>The speed we use for this will be
where we =0A spend most of the time, not stall speed and not top speed, bu
t climb and =0A normal cruise speed. So in this range the airfoil should h
ave the lowest drag, =0A if it was an airliner that spend most of its time
climbing and cruising at =0A high altitude at low indicated speed it will
be at similar CL most of the time =0A (but Mach Nr will play its =0A rol
l)=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>All aircrafts =0A
that see any production see an increase in installed power and weight. If
this =0A was in the design of the KIS from start I don=99t know, bu
t the prototype had a =0A Limbach from start if understand it correctly, a
nd several hundred lbs less =0A weight.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A
>=0A>=0A>=0A>=0A>=0A>Most seem to =0A have the I0-240B engine installed no
w and a MTOW of 1450 lb or so. And it =0A is=0A>cruising at around 140 kts
. This give an lift coefficient, of around CL =0A 0.3 at cruise, it mean t
hat an airfoil with higher camber would have been =0A better then the curr
ent N-63A215, where the 3:d last digit tell the designed =0A CL So it have
an airfoil designed for higher speeds, but no meaning to have =0A that, n
o one cruise at WOT at SL, but most cruise at 65-75% power from 2000=C2=B4
=0A to 8000 or 12000=C2=B4=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>
=0A>=0A>The =0A NACA 6x- series isn=99t the best with today standard
, rumour says that the NACA =0A screwed up when publishing these new airfo
ils with a faulty design that they =0A could not take back.=0A>=0A>=0A>=0A
>=0A>=0A>=0A>=0A>An Harry Riblett GA-37A315 =0A would be a better choice,
it have gentler stall, and will show less drag at =0A both cruise and clim
b, The difference between Riblett and NACA is that the =0A nose radii is p
laced correctly on the Riblett. The Riblett will have about =0A 7-8% highe
r=0A>CLmax.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>I =0A d
raw up both airfoils for evaluation and when aligning the portion where mai
n =0A and after spar will be, it is a different of 1 degree at the chord l
ine. (From =0A nose radii to trailing =0A edge)=0A>=0A>=0A>=0A>=0A>=0A>
=0A>=0A>=0A>=0A>=0A>=0A>The NACA is in =0A Green=0A>=0A>=0A>=0A>=0A>=0A>
=0A>=0A>=0A>=0A>=0A>=0A>>From the main spar =0A and back there is very lit
tle difference in shape, meaning the lift at same =0A angle will be about
the same with this difference in =0A angle=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>
The chord line is just a reference line =0A that is convenient to draw and
measure, but aerodynamically it is almost a =0A fictive line, the importa
nt line or angle of an airfoil is the zero lift =0A angle, from this line
the lift is generated if it is given an angle to the =0A relative wind, th
ink of an symmetric airfoil where the zero lift line and =0A chord line is
the same, and at alpha zero it will not produce =0A any=0A>lift.=0A>=0A>
=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>An airfoil =0A with camber
will produce lift even if the chord line is at alpha zero, or =0A slightl
y negative, because the zero lift line will have a positive alpha to =0A t
he wind.=0A>=0A>=0A>=0A>To make a cambered airfoil to produce zero lift, th
e =0A nose have to be lowered until the zero lift line is parallel to the
wind, so =0A an cambered airfoil is said to have a zero lift angle of minu
s some degree =0A depending of the camber, it can be -1 to -6 degree on co
mmon airfoils and =0A camber.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>
=0A>=0A>=0A>=0A>=0A>=0A>=0A>The =0A NACA 63A-215 have a zero lift angle of
-1.64 degree, and the Riblett GA-37A315 =0A -2.14 degree.=0A>=0A>=0A>=0A>
A difference of 0.50 =0A degree.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>The lift s
lope Cl alpha=C2=B4 is depending =0A on the wing aspect ratio, for a AR of
6, the slope of the lift curve is CL=C2=B5 = =0A 2Phi / 1+2/A2 = 2Phi
/ 1 + 2 / 6 = 4.71239 per =0A radian=0A>=0A>=0A>=0A>Or=0A>4.71239 / 57.
3 = 0.08224 per =0A degree=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>The original w
ing is 3 degree up from =0A chord line to fuselage reference line, so if w
e fly it with the reference line =0A horizontal the wing CL=C2- =C2- i
s 3 - -1.64 = 4.64 degree a 0,08224 = =0A 0,38 CL.=0A>=0A>=0A>=0A>=0A>
=0A>=0A>=0A>The GA-37A315 will be 1 degree less =0A measured at the chord
line, so 2 - -2.14 = 4.14. so CL with fuselage level =0A will be 0.34=0A
>=0A>=0A>=0A>It means that at higher speeds the nose down angle =0A will b
e 0.5 degree less.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>Lets say we cruse at =0A
165 MPH TAS @ 8000=C2=B4 and 1450 Lb the CL will be 0.30 plus the fact tha
t the =0A wing have to carry the down force from tail plane. Both airfoils
have a =0A negative pitch moment of 0.05, the Riblett just a little more
then the NACA =0A due to more camber.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>
=0A>The load at the =0A tail is its moment times the wing chord and area,
times dynamic =0A pressure.=0A>=0A>=0A>=0A>Divided with=0A>tail length.=0A
>=0A>=0A>=0A>It will =0A be about 84-85 lb down force at cruise if CG is a
t 25% chord=0A>=0A>=0A>=0A>So =0A the wing then will carry 1535 lb or CL
=C2- =0A 0.32=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>A CG further back will redu
ce negative =0A lift and then reduce induced drag. (And reversed.)=0A>=0A>
=0A>=0A>1450 lb at =0A after limit will reduce down force at the tail with
10 lb=0A>=0A>=0A>=0A>at =0A forward limit it will ad 35 lb to a total lif
t the wing have to do of 1570 lb =0A or CL 0.33=0A>=0A>=0A>=0A>=0A>=0A>=0A
>=0A>A CG to forward and the elevator =0A will not be able to hold the nos
e up with flaps, to far back and it will be =0A sensitive on the stick. Th
en we come into:=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>Nose =0A drop at landing,
sounds like ground effect, when closer to ground the down =0A wash from wi
ng is flattened out, meaning the tail will have less down =0A force.=0A>
=0A>=0A>=0A>With a horizontal stab area of just a bit over 17% of =0A the
wing area, seems small, even if the tail arm=0A>is =0A long.=0A>=0A>=0A>
=0A>One reason for the elevator not be up to the job can also =0A be the t
ail incidence, 0.5 - 0.75 degree down might help.=C2- (but hard to =0A f
ix that now)=0A>=0A>=0A>=0A>Seems like, longer elevators chords is a good
=0A thing, 1,75=9D longer chord move the hinge line to 60% chord/40%
elevator.=C2- =0A (about =9Cnormal=9D)=0A>=0A>=0A>=0A>And V
G's, seems to help, it means something is =0A wrong from start, to small e
levator or wrong incidence. Or to small H.- tail =0A area or all three.=0A
>=0A>=0A>=0A>=0A>=0A>=0A>=0A>The Wing =93 Fuselage fairing =0A shoul
d be expanding and 10% of the chord at the trailing edge, according to =0A
Raymer, It mean in my eyes it should be 10% of the local chord, so mid cho
rd =0A it is 5% of the total chord =0A length.=0A>=0A>=0A>=0A>=0A>=0A>=0A
>=0A>=0A>=0A>=0A>=0A>=0A>=0A>I don=99t see =0A anyone on Matronics t
alks about if they sealed the control surface hinge gaps =0A with tape. Th
at will make a big difference. Tape them with Tesa fabric =0A tape=0A>on t
he bottom side of the Hinge line, inside the elevator, inside the =0A rudd
er, inside the aileron, and bottom of the flap hinge =0A line.=0A>=0A>=0A>
=0A>=0A>=0A>=0A>=0A>=0A>=0A>Having them unsealed=C2- is =0A like driving
with the parking brake on.=0A>=0A>=0A>=0A>On a Kitfox it is the =0A diffe
rence of being able to make a 3-point or not with or without sealing the
=0A elevator gap.=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>Jan Carlsson=0A>=0A>=0A>
=0A>JC =0A Propeller Design=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>Ps. Sorry to sa
y, I have never =0A been onboard a =0A KIS.=0A>=0A>=0A>=0A>=0A>=0A>=0A>
=0A>--------=0A>=0A>=0A>=0A>www.jcpropellerdesign.com=0A>=0A>=0A>=0A>=0A>
=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>Read =0A this
topic online =0A here:=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>http://forums.matron
ics.com/viewtopic.php?p=392088#392088=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>=0A>
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Subject: | Re: KIS TR-1 Airfoil |
Thanks Mark, I'm going to bed and get a good nights sleep.
Jesse
In a message dated 1/14/2013 8:47:24 P.M. Mountain Standard Time,
sstearns2@yahoo.com writes:
Hi Jesse,
Mark's numbers are based on part 23 certified airplane loads. Which means
a 100 pound push/pull on the control stick. I doubt I have or will ever
pull more than 20 pounds on my stick. If I were designing an airplane I
would use part 23 control loads, but it probably isn't anything to lose sl
eep
over in our kisi.
Scott
From: "Flyinisfun@aol.com" <Flyinisfun@aol.com>
Sent: Monday, January 14, 2013 6:08 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
This is Jesse,
I built and used the materials that came with the kit. I achieved the
degrees of up elevator called for in the prints. How close the down arm f
rom
the elevator comes to hitting something I don't know now. "I'm surprised
these problems didn't surface before now. Maybe they did and I missed the
m,
which is it? I'm assuming we're still talking about the TR-1.
In a message dated 1/14/2013 6:49:26 P.M. Mountain Standard Time,
mantafs@earthlink.net writes:
--> KIS-List message posted by: Mark Kettering <mantafs@earthlink.net>
The current aft elevator tube is 6061 T6, 120" long, 1.25" dia, 0.065"
wall with a margin of safety of -0.39. FYI, the forward steel tube is 413
0,
51.25" long, 0.74" dia, 0.035" wall with a margin of safety of -0.35. The
margin of safety must be positive to be safe.
Steel or aluminum is a wash for weight to stiffness ratio. But for the
long elevator tube to be 1" dia steel it would need to be 0.075 wall or
thicker. This would make it over 6 times more heavy than the aluminum tub
e
(about 10 lbs more) and only give you 0.125" more clearance on the horizon
tal.
Diameter really helps for tube compression buckling resistance.
Using two tubes really reduces the load. If 2 tubes were used and they
were each 60" long they could be 6061 T6, 1" dia, 0.058" wall and still ha
ve
a 0.11 margin of safety.
As Scott said, double tapered would really help.
I think the most simple solution is to increase the length of the rudder
control horn (from 4' to 5") and slightly change the idler ratio (change th
e
long side to 5"). Not only does this increase the clearance but it also
reduces the load on the push tube. Still not a positive margin but only
about half as negative.
Mark
-----Original Message-----
From: Scott Stearns
Sent: Jan 14, 2013 4:37 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
Another option would be to make a reducer fitting and transition to a
smaller tube for the portion that goes under the horizontal. An ideal pus
h
tube is tapered and you only need the full diameter at the center. The
fantasy push tube is tapered unidirectional boron fiber. Can someone post
the
tube length and diameter/wall thickness and the distance from the LE of th
e
horizontal tail to the point where the tube bolts to the elevator? Another
option is to switch the whole tube to a smaller diameter steel tube. It
would be the easiest solution, but it would add some wieght. 3-4 pounds
probably. My
forward pitch control tube is 3/4" diameter steel on my much modified TR-1
to minimize the width of the center console. Scott
From: Mark Kettering <mantafs@earthlink.net>
Sent: Monday, January 14, 2013 12:43 PM
Subject: Re: KIS-List:
KIS TR-1 Airfoil
>From my calculations when I worked for Tri-R, the elevator push pull tube
was undersized for it's length. Then talking with Vance it came up that
the up throw was well less than calculated due to contact between the push
tube and horizontal. The solution talked about was to put an additional
idler well aft in the fuselage and as low as possible and then the most af
t
tube would no longer contact the horizontal. This would solve two issues
at
the same time.
I also like the idea of increasing the length of the control arm on the
elevator and changing the ratio on the current idler. This would reduce t
he
load on the push tube and increase the clearance from the tube to the
horizontal.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:34 PM
Subject: Re: KIS-List: KIS TR-1 Airfoil
As far as I can tell it is stock as per the plans. Maybe that is why the
VG's made a significant difference. Galin
On Sun, Jan 13, 2013 at 2:12 PM, Mark Kettering <mantafs@earthlink.net>
wrote:
--> KIS-List message posted by: Mark Kettering <mantafs@earthlink.net>
Hello Galin,
Is your elevator linkage stock as per the plans or modified to allow for
more up elevator? I think this modification is very important and may
prevent the need for VG's. The stock method had the control tube hit the
bottom
of
the horizontal inside the tail before a reasonable up elevator deflection
limit could be reached.
Mark
-----Original Message-----
From: Galin Hernandez
Sent: Jan 13, 2013 10:20 AM
Subject: Re: KIS-List: KIS TR-1 Airfoil
Jan; What do you mean when you say "Tape them with Tesa fabric tape on the
bottom side of the Hinge line, inside the elevator, inside the rudder,
inside the aileron, and bottom of the flap hinge line." Can you provide a
photo of what you mean? This sounds like a viable option for those of us t
hat
have flying airplanes and can't re-work the wing/tail.
I used the VG's from Stolspeed.com on the elevator and they
made a significant improvement while landing my TR-4.
GalinN819PR
On Fri, Jan 11, 2013 at 4:36 PM, Propellerjan <propellerdesign@tele2.se>
wrote:
KIS TR-1 Airfoil
In the search for information to calculate an optimum propeller for the
KIS I0-240 I found a lot of information and thoughts about its handling
especially during landing.
When picking an airfoil for a airplane project that is about the last
thing to do before the design is set in stone. The wing area is determined
in
respect of stall speed with flap arrangement.
When
having MTOW, wing aspect ratio and wing area, we can calculate speed and
lift coefficient, CL
The speed we use for this will be where we spend most of the time, not
stall speed and not top speed, but climb and normal cruise speed. So in th
is
range the airfoil should have the lowest drag, if it was an airliner that
spend most of its time climbing and cruising at high altitude at low
indicated speed it will be at similar CL most of the time (but Mach Nr wil
l play
its roll)
All aircrafts that see any production see an increase in installed power
and weight. If this was in the design of the KIS from start I don=99
t know,
but the prototype had a Limbach from start if understand it correctly, and
several hundred lbs less weight.
Most seem to have the I0-240B engine installed now and a MTOW of 1450 lb
or so. And it is
cruising at around 140 kts. This give an lift coefficient, of around CL
0.3 at cruise, it mean that an airfoil with higher camber would have been
better then the current N-63A215, where the 3:d last digit tell the design
ed
CL So it have an airfoil designed for higher speeds, but no meaning to hav
e
that, no one cruise at WOT at SL, but most cruise at 65-75% power from
2000=C2=B4 to 8000 or 12000=C2=B4
The NACA 6x- series isn=99t the best with today standard, rumour say
s that
the NACA screwed up when publishing these new airfoils with a faulty desig
n
that they could not take back.
An Harry Riblett GA-37A315 would be a better choice, it have gentler
stall, and will show less drag at both cruise and climb, The difference be
tween
Riblett and NACA is that the nose radii is placed correctly on the Riblett
.
The Riblett will have about 7-8% higher
CLmax.
I draw up both airfoils for evaluation and when aligning the portion where
main and after spar will be, it is a different of 1 degree at the chord
line. (>From nose radii to trailing edge)
The NACA is in Green
>From the main spar and back there is very little difference in shape,
meaning the lift at same angle will be about the same with this difference
in
angle
The chord line is just a reference line that is convenient to draw and
measure, but aerodynamically it is almost a fictive line, the important li
ne
or angle of an airfoil is the zero lift angle, from this line the lift is
generated if it is given an angle to the relative wind, think of an symmet
ric
airfoil where the zero lift line and chord line is the same, and at alpha
zero it will not produce any
lift.
An airfoil with camber will produce lift even if the chord line is at
alpha zero, or slightly negative, because the zero lift line will have a
positive alpha to the wind.
To make a cambered airfoil to produce zero lift, the nose have to be
lowered until the zero lift line is parallel to the wind, so an cambered a
irfoil
is said to have a zero lift angle of minus some degree depending of the
camber, it can be -1 to -6 degree on common airfoils and camber.
The NACA 63A-215 have a zero lift angle of -1.64 degree, and the Riblett
GA-37A315 -2.14 degree.
A difference of 0.50 degree.
The lift slope Cl alpha=C2=B4 is depending on the wing aspect ratio, for a
AR
of 6, the slope of the lift curve is CL=C2=B5 = 2Phi / 1+2/A2 = 2Phi /
1 + 2 / 6
= 4.71239 per radian
Or
4.71239 / 57.3 = 0.08224 per degree
The original wing is 3 degree up from chord line to fuselage reference
line, so if we fly it with the reference line horizontal the wing CL is
3 -
-1.64 = 4.64 degree a 0,08224 = 0,38 CL.
The GA-37A315 will be 1 degree less measured at the chord line, so 2 -
-2.14 = 4.14. so CL with fuselage level will be 0.34
It means that at higher speeds the nose down angle will be 0.5 degree
less.
Lets say we cruse at 165 MPH TAS @ 8000=C2=B4 and 1450 Lb the CL will be 0
.30
plus the fact that the wing have to carry the down force from tail plane.
Both airfoils have a negative pitch moment of 0.05, the Riblett just a lit
tle
more then the NACA due to more camber.
The load at the tail is its moment times the wing chord and area, times
dynamic pressure.
Divided with
tail length.
It will be about 84-85 lb down force at cruise if CG is at 25% chord
So the wing then will carry 1535 lb or CL 0.32
A CG further back will reduce negative lift and then reduce induced drag.
(And reversed.)
1450 lb at after limit will reduce down force at the tail with 10 lb
at forward limit it will ad 35 lb to a total lift the wing have to do of
1570 lb or CL 0.33
A CG to forward and the elevator will not be able to hold the nose up with
flaps, to far back and it will be sensitive on the stick. Then we come
into:
Nose drop at landing, sounds like ground effect, when closer to ground the
down wash from wing is flattened out, meaning the tail will have less down
force.
With a horizontal stab area of just a bit over 17% of the wing area, seems
small, even if the tail arm
is long.
One reason for the elevator not be up to the job can also be the tail
incidence, 0.5 - 0.75 degree down might help. (but hard to fix that now)
Seems like, longer elevators chords is a good thing, 1,75=9D longer
chord
move the hinge line to 60% chord/40% elevator. (about =9Cnormal
=9D)
And VG's, seems to help, it means something is wrong from start, to small
elevator or wrong incidence. Or to small H.- tail area or all three.
The Wing =93 Fuselage fairing should be expanding and 10% of the cho
rd at
the trailing edge, according to Raymer, It mean in my eyes it should be 10
%
of the local chord, so mid chord it is 5% of the total chord length.
I don=99t see anyone on Matronics talks about if they sealed the con
trol
surface hinge gaps with tape. That will make a big difference. Tape them w
ith
Tesa fabric tape
on the bottom side of the Hinge line, inside the elevator, inside the
rudder, inside the aileron, and bottom of the flap hinge line.
Having them unsealed is like driving with the parking brake on.
On a Kitfox it is the difference of being able to make a 3-point or not
with or without sealing the elevator gap.
Jan Carlsson
JC Propeller Design
Ps. Sorry to say, I have never been onboard a KIS.
--------
www.jcpropellerdesign.com
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