Mr. Monkey King, I built a 60" HLG using Mark Drela's AG03. It's 6.24% thick and 2.0% camber. Launch and run are tremendous. Should be a good choice for you. Mr. Drela likes to keep his airflow attached and sacrifices some high lift coefficient float for low drag at speed. I think that a look at his Apogee glider on http://www.charlesriverrc.org will give you some idea of the plane that can take advantage of this thin airfoil.
If you end up cutting them or getting them cut, I would suggest that you take a good look at the AG04 which does not "simplify" the section so that it is easy to make out of wood. Refer to the March 2003 issue of Model Aviation if you have it (you are an AMA member, right?). It is a "comprehensive" list of Mark Drela's airfoils and applications. FYI, a 30" plane with a 5" average chord traveling at 20 fps(floating) is at a Re of 53,000, at 40 fps (moving) it's 106,000. The reduced Re (which is what is how the article categorizes the airfoils) is about 66,000 at all speeds if you are at about 12 oz. For anyone interested in what a reduced Reynolds number is.... Re is proportional to speed. Cl (lift coefficient) is proportional to 1/(speed squared). If you multiply the Re by the square root of the Cl, you get a characteristic that is no longer speed dependent. The only catch now is that it is for a specific plane with a given span, wing area, planform, weight, etc. You can get an estimate of the reduced Re at this web site - http://soaring.cnde.iastate.edu/calcs/frames.shtml - and compare the airfoils on YOUR model at ALL speeds. The limitation is the number of airfoils. Maybe we can get them to add more to their database. I go there often. Good luck and keep designing the planes of the future. I know too many people who "don't build anymore". Tom Koszuta Clarence Sailplane Society (Buffalo) NY http://www.bufflink.com/css/ PS. I highly recommend Martin Simon's book, Model Aircraft Aerodynamics. I have read it, in pieces, about a half dozen times. There are a few holes in it on stability, but the lift and drag and camber and washout and separation bubbles and... stuff is really good. ----- Original Message ----- From: "Brian Chan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, November 01, 2002 1:34 PM Subject: Re: [RCSE] Makin' wings and lookin' for advice. > At 12:50 PM -0500 11/1/02, Monkey King wrote: > >I'm working on a 1m scratchbuild for bombing around on our surly New > >England slopes, and I have a couple of questions. > > > > > >2: I'd like to have my cores computer cut. Someone posted to the list a > >couple of months ago about cutting cores, but I've lost the address. > >Could I get a sound-off about who people use? > > > > However the core is cut, by hand (over template) or comuputer, the > accuracy come from how you finish the wing. Couple passed of the > sanding block will send all the accuracy out the window. > > Brian > -- > Brian Chan, > An Electric Airplane Junkie @ San Mateo.Ca.USA > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
