Today's Message Index:
----------------------
1. 05:47 PM - Re: Grumman airfoil (Bruce Smith)
2. 11:04 PM - Re: Grumman airfoil (Gary L Vogt)
Message 1
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| Subject: | Re: Grumman airfoil |
Gary,
Question. Are you going to design a new, semi-Cirrus like wing for the Grumman
4 seater line? You did say "I like doing stuff like this", and that you have tooooooo
much time on your hands.
Bruce
On Jul 3, 2012, at 11:59 PM, Gary Vogt wrote:
> Under the heading of way too much time on my hands and a curiosity that won't
let me leave this topic alone, I've been converting to CAD the dimensions of
several NACA airfoils and matching them to the Grumman airfoil. Going on the
premiss that the original AA1 had a 64-415 airfoil, I laid out a drawing to match
it as close as possible.
>
> The original AA1 airfoil is close to the 64-415, but it isn't really a 64-415.
Using that same airfoil, and drooping the nose so that the nose was parallel
to the "0" waterline and then extending that line to the spar, well, let's just
say, it's an interesting airfoil, but nothing close to a 64-415.
>
> Then, adding the flaps and ailerons from a Tiger and you have a completely new
airfoil. It's skinnier than a 64-415 and fatter than a 64-412. So, I algebraically
added the points of both the 64-415 and 64-412 airfoils and divided by
2. In theory, a 64-413.5. This airfoil is damn close to the Grumman airfoil
with the exception of the flat bottom from the nose to the spar. However, the
spar location makes it a 63.5-413.5 or something similar.
>
> That's why I wanted some good locations. I still need them if you have the time
and patience.
>
> From the looks of it, the Grumman airfoil actually a pretty decent airfoil.
Much thinner than the -415 and a longer upper surface with a nice gentle curve.
The -415 has a rather steep curve past the 40% chord peak.
>
> Comparing it to a Clark-Y one needs to begin making assumptions on installed
incident angles and the fact that the -Y is flatter on the bottom.
>
> Interesting.
>
> Feedback appreciated.
>
>
>
Message 2
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| Subject: | Re: Grumman airfoil |
I'll tell you want I would really like to do. I would like to have the reso
urces to build a full scale de Havilland DH.98 Mosquito. but out of carbon f
iber. To power it, I would hire Falconer to work with Walden to build a 2400
cubic inch V12 with a goal of 4000 horsepower with nitrous and 2000 without
.
But since I'm poor, I'll just draw pictures.
Save your pennies for an IO360 and constant speed prop for your Tiger.
Gary
Sent from my iPad
On Jul 10, 2012, at 5:47 PM, Bruce Smith <haveblue1@mac.com> wrote:
> Gary,
>
> Question. Are you going to design a new, semi-Cirrus like wing for the Gru
mman 4 seater line? You did say "I like doing stuff like this", and that you
have tooooooo much time on your hands.
>
> Bruce
>
> On Jul 3, 2012, at 11:59 PM, Gary Vogt wrote:
>
>> Under the heading of way too much time on my hands and a curiosity that w
on't let me leave this topic alone, I've been converting to CAD the dimensio
ns of several NACA airfoils and matching them to the Grumman airfoil. Going
on the premiss that the original AA1 had a 64-415 airfoil, I laid out a dra
wing to match it as close as possible.
>>
>> The original AA1 airfoil is close to the 64-415, but it isn't really a 64
-415. Using that same airfoil, and drooping the nose so that the nose was p
arallel to the "0" waterline and then extending that line to the spar, well,
let's just say, it's an interesting airfoil, but nothing close to a 64-415.
>>
>> Then, adding the flaps and ailerons from a Tiger and you have a completel
y new airfoil. It's skinnier than a 64-415 and fatter than a 64-412. So, I
algebraically added the points of both the 64-415 and 64-412 airfoils and d
ivided by 2. In theory, a 64-413.5. This airfoil is damn close to the Grum
man airfoil with the exception of the flat bottom from the nose to the spar.
However, the spar location makes it a 63.5-413.5 or something similar.
>>
>> That's why I wanted some good locations. I still need them if you have t
he time and patience.
>>
>> =46rom the looks of it, the Grumman airfoil actually a pretty decent airf
oil. Much thinner than the -415 and a longer upper surface with a nice gent
le curve. The -415 has a rather steep curve past the 40% chord peak.
>>
>> Comparing it to a Clark-Y one needs to begin making assumptions on instal
led incident angles and the fact that the -Y is flatter on the bottom.
>>
>> Interesting.
>>
>> Feedback appreciated.
>>
>>
>> href="http://www.matronics.com/Navigator?TeamGrumman-List">http://www.m
atronics.com/Navigator?TeamGrumman-List
>> href="http://forums.matronics.com/">http://forums.matronics.com
>> href="http://www.matronics.com/contribution">http://www.matronics.com/c
ontribution
>>
>
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