Date: Wed, 8 Feb 1995 21:31:39 -1000 From: hzsdc31!pverkel@hzsda01.att.com (P C Van Erkel +1 35 87 4602) Message-Id: <9502090731.AA11029@hzsda01> Organization: Harvard University Office of Information Technology Subject: arafoParafoil Profile Mark Pelletier asks: >Can anyone recommend a reasonable profile/keel scheme for a kite of >these dimensions? I've heard of an airfoil plotting program >(PLOTFOIL?) but have been unable to locate a copy...does anyone know >where I might find a copy? I have a copy of a GWBASIC program written to calculate NACA profiles. The (old) NACA notation of a profile is quite simple. It use four digits to calculate the shape of the profile. Example: NACA 2412 first digit gives the arc of the profile in percent of the profile length second digit position of this point in percent of the profile length third and forth digit thickness of the profile in percent of the profile length. Once a NACA profile is chosen, this program is very helpful in scaling ribs for parafoils. Or if you have a profile, you can measure these three NACA points, and than scale to any rib length. For those who like to try it, mail for a copy. Peter van Erkel pverkel@hzsda01.att.com = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 8 Feb 1995 23:36:55 -1000 From: crowell@teleport.com (Carl Crowell) Message-Id: Organization: Kites By Carl Crowell Subject: Re: arafoParafoil Profile In all of your research, please remember that what you want is a very low speed airfoil. I have seen people come up with airfoils that are "super-foils" designed to have optimum lift at trans-sonic speeds. What they don't realize is that at those speeds, lift is not so much a problem as drag... Most single line kites rarely have a wind speed above 50kph. I rarely fly in wind above 35kph. An airfoil for a plane with a stall speed of 100+kph may not be the way to go..... ___________________________________________________ email: crowell@kite.com FTP: ftp.teleport.com/pub/users/crowell WWW: http://www.teleport.com/~crowell Kites By Carl Crowell - O.S.F.M. World Headquarters = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Sat, 11 Feb 1995 20:52:30 -1000 From: andrew@tug.com (Andrew Beattie) Message-Id: Organization: /usr/lib/news/organisation Subject: Re: arafoParafoil Profile hzsdc31!pverkel@hzsda01.att.com (P C Van Erkel +1 35 87 4602) writes: >Once a NACA profile is chosen, this program is very helpful in scaling >ribs for parafoils. Or if you have a profile, you can measure these three >NACA points, and than scale to any rib length. Remember, of course, that when using soft kite technology, the shape of the skin may bear only a passing resemblance to the shape of the rib... Andrew -- Does a Rev War Kite have 4 lines and fly on Manja? o /\ Kite Jumping: Read the Kite FAQ's: ftp.hawaii.edu:/pub/rec/kites/faq |_ \/ If you want For sale: Prototype Keelless Rowlands Flowform. US$80 (_\ to fly, use a Kite Fliers Site: http://www.kfs.org/kites andrew@tug.com Hangglider = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Tue, 14 Feb 1995 07:17:07 -1000 From: Mark Pelletier Message-Id: <3hqoij$dcf@news.sanders.lockheed.com> Organization: Lockheed Sanders Subject: Re: arafoParafoil Profile Thanks for your reply...I will take a look at the GWBasic (boy, that's a blast from the past!). If the info appears useful I may attempt to update the code to a Visual Basic executable...If that ever happens I'll be sure and get your and Uwe Weber's concurrence prior to posting the file here or on the Hawaii archive. By the way... I was able to locate PLOTFOIL on one of the SimTel mirrors several days ago. I downloaded the file and gave the app. a few tries (I'll admit I did not read the documentation very carefully!) but could not see how it would apply to my immediate task of laying out a parafoil profile...and the app didn't really invite me to continue...so I trashed it (oh well...). For now, I think I'm gonna' continue to use my old standby's (graph paper, ruler and flexible fiberglass rod for drawing curves). I did learn from a couple of replies to my oringinal posting that scaling existing parafoil profiles should work fine...I've done that and the profile looks fine...we'll see how it flies! See ya', Mark Pelletier mjpellet@mailgw.sanders.lockheed.com = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =