---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Sat 05/10/08: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:49 PM - GN-1 airfoil information (jimd) ________________________________ Message 1 _____________________________________ Time: 02:49:53 PM PST US Subject: Pietenpol-List: GN-1 airfoil information From: "jimd" Hi, Just had an A&I leave my house after looking over my biplane GN-1 project. He had a concern about the landing gear placement of my plane, based on the weight/placement of the engine. To correctly determine where the gear should be he said I needed to find out where the CG of the plane is, but with it being a biplane configuration, he said that I needed to have the mean center of lift information for both the upper and lower wings, as well as a number of measurements from the assembled plane, like information about the spacing horizontally between the wings. Then once the weights, and measurements are known, the acceptable range of locations for the axle of the landing gear can be determined from some engineering formulas. Did some searching, found two engineering articles on finding the CG/center of lift on biplanes, and they require information about the airfoil. I was able to find information on the Pietenpol FC-10 airfoil, which I believe is what my lower wing has, as the Aerial biplane conversion plans say the airfoil is the same. http://www.airminded.net/piet/piet.html has piet airfoil info with Cl,Cm,Cd, type info. However presuming my plane has the Gregga airfoil, which the plans say have a rounder leading edge.. and which appear to be thicker.. I would think it is a different airfoil, with different values. Have not seen it listed in the common airfoils databases. Anyone have information on the GN-1 airfoil? I have the plans, have a jig, and wings, but only can guestimate it as being like the piet. We are thinking I may have to rework the landing gear to get it right, but no one knows how much if any it must be changed. So any GN-1 ordinates, or the Cl,Cm,Cd type info, or naca airfoil numbers... anything like that would be helpful. You can see my gear/plane on the westcoastpiet site, its under Jim D. Thanks, Jim Read this topic online here: http://forums.matronics.com/viewtopic.php?p=182401#182401 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-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/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-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.