---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Tue 07/10/12: 2 ---------------------------------------------------------- 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 _____________________________________ Time: 05:47:58 PM PST US From: Bruce Smith Subject: Re: TeamGrumman-List: 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 _____________________________________ Time: 11:04:16 PM PST US Subject: Re: TeamGrumman-List: Grumman airfoil From: Gary L Vogt 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 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 >> > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message teamgrumman-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/TeamGrumman-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/teamgrumman-list Browse Digests http://www.matronics.com/digest/teamgrumman-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.