John. So it turns into a Chevy Ford fiasco again? I have some top fliers commenting on the Sharon. They must feel it when they fly to different airfoils like you said. So the foil with less camber is easier to change the TE flight characteristics and the plane with more camber is harder?
Thanks for the education, Don -----Original Message----- From: John Erickson [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 08, 2005 10:47 AM To: Don & Lisa Copley; Soaring List Subject: Re: [RCSE] Airfoil question Don, A lot of the airfoils will reference numbers that have to do with 2 things: Camber and Thickness. The Zenith has a HQW 3.5/8. The HQW part is the author, in this case Helmut Quabeck. The 3.5 is the percent camber, and the 8 is the percent thickness. In general, the greater the camber, the more lift but at a price of more drag. Where you really see it is in windy conditions or when you are trying to go fast. Trying to make the best of both worlds, the designers have set up the airfoils so you can change the trailing edge of the wing (reflex or camber) hence changing the airfoil. A reflexed airfoil is going to scoot across the sky better, but not have as much lift. Some of the differences between airfoils are so small that only as a more experienced pilot will you notice a difference. There are other factors like the wing planform (shape) that also come into play. So...the MH32 has less camber than the HQW 3.5/8 which in turn has less than the 7037. That's probably the order you would put them in general terms if you are talking about drag and lift. Your final sentence sums it all up. If you practice 3 times a week (lucky man) it won't really matter what foil your plane has. A good pilot can make a number of foils "work", it just comes down to preference and flying style. JE -- Erickson Architects John R. Erickson, AIA > From: "Don & Lisa Copley" <[EMAIL PROTECTED]> > Date: Tue, 8 Mar 2005 02:41:26 -0600 > To: <[email protected]> > Subject: [RCSE] Airfoil question > > Over the past week we have gone from Artemis to Zenith's in what to fly > discussion category. > > It's boiled down to two things: > 1.) it's a tool use it...practice, practice practice > 2.) ...and airfoil > > What is the difference between (Zenith etc.) MH-32 and (Sharon Pro) SD 7037 > which turn into a RG15. This is Greek to me. I don't have aerodynamics > degree but it seems pretty important for what your airplane can do and can > do in a contest environment...yes, I will have practice at least three times > a week. > > Don > > > 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. Email sent from web based email such as Hotmail and AOL are > generally NOT in text format 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. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
