Is the problem the term aspect ratio? For his project he's probably using a plank wing. Aspect ratio is a term that can be applied. What happens to the same span if the planform becomes elliptical? Do you still apply the same aspect ratio?
Out of practical experience there is a big difference between a plank and an ellipse, even with the same foil (most noticeable at higher speeds). I think we've spun away from the original premise of how aspect ratio and glide rate are related, but it's obvious that more variables quickly come into effect. I did a similar science fair project in high school where I tried two different foils on the same planform and airframe. I used the school gym, turned out the lights and recorded the flight by leaving my camera lens open and using a strobe light. The project basically proved that the break through airfoil I was trying didn't work at all. The fact that I got to integrate a glider and photography was probably more important. I still have one of my favorite pictures, where the glider was flown, banked hard left towards the camera and flew by, all recorded by the strobe. I think I was blinking for about a week after that project. JE -- Erickson Architects John R. Erickson, AIA > > I stand by my previous statement: that total induced drag does not depend on > the > AR for a fixed span (which is aero 101 really). > And I just learned something about English units! > Best regards, > Oleg. > 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
