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Al,
I dont have an email address for Joe Wurtz, but maybe someone out there can hook you two up. Joe is a fellow Cal Poly Aero and a really smart guy. Back in school he could do things with his R/C sailplane that were just amazing. Stan Fisher "Cameron" news:yskt5.13988$Qx4.660874@news1.rdc1.il.home.com... > I will put on my flame retardant suite before I say this... One my many > other passions is radio controlled soaring. A very well known R/C sailplane > pilot (and previous world champion), by the name of Joe Wurts, has > successfully been experimenting with dynamic soaring for some time now. Joe > has managed to fly a R/C glider using dynamic soaring for EXTENDED periods > of time. For more information, see the email archive list at the following > links: > > http://www.egroups.com/listsaver/soaring/ > http://www.eclipse.net/~mikel/rcse/rcse.htm > > Thank you. > > Cameron > > > > > > "Al Bowers" > news:tt1yyyftpu.fsf@orville.dfrc.nasa.gov... > > > > I had the great fortune to listen to Gary Osoba talk at the Western > > Homebuilders Workshop this weekend about his latest work on dynamic > > soaring. I may be overstating the case, but I believe Gary (and Taras > > Kiceniuk Jr) are onto something, perhaps as fundamentally challenging > > as Paul MacCreadys original speed ring idea. > > > > While the decription sounds like the "dolphin flying" which were > > accustomed to, it is different for some radically different reasons. > > Gary and Taras think that it is necessary to fly at very high speeds, > > which rotates the lift vector very far forward. Drag is also rather > > large, so the resultant of lift and drag opposes gravity. But when a > > small vertical component of airt is encountered, the effect is to > > rotate the lift vector further forward. At this time, Gary performs a > > very strong pull, increasing G on the airframe to about 2. As soon as > > the following sink is encountered, Gary perfoms a push to 0 G. the > > theory from Taras says that sink should be countered with negative G, > > but Gary feels that an error in timing would destroy any gains he has > > made, while 0 G imposes no induced drag penalty (or minimizes the > > total drag penalty is probably a better way to put that). Gary is > > using this technique on the old Sigma open class variable geometry > > sailplane that was modified by Professor Marsden. > > > > Gary showed some data taken with an integrated GPS/barograph unit. In > > the first segment, he flew at something over 120 mph, using his 2G > > pull and 0G push technique. At the end of a 12 mile segment, he had > > lost 1000 ft of altitude. So he stopped and thermalled up (as Gary > > puts it, "thermalling is a waste of time"). Gary felt that perhaps he > > had not rotated the lift vector far enough forward, so in the second > > segment, he pushed his speed up to 183 mph. In this 16 mile run, he > > GAINED altitude. But the maneuvering is VERY dynamic, the push/pulls > > are coming every 14.4 seconds with altitude variations of 1000+ ft > > everytime. Gary described the lift that day as very normal, with no > > streeting or organization. The data was astounding. > > > > Perhaps the old adage (Ive usually heard it credited to George > > Moffat) of "fly straight ahead and climb" should be revised to "fly > > straight a head, push, pull, and climb." If you get a chance to see > > this talk, please do so. > > > > Thinking about it, it requires a coupling of the airmass (total energy > > vario, but without filtering), the sailplanes polar (at various G > > levels), and the airspeed. Gary says that the math indicates an > > optimum G level which rapidly exceeds the ability of the sailplane (or > > pilot) to perform. But even with "moderate" 2G/0G technique gary is > > flying seems to work. I could see where an LED light system operated > > by those instruments and a microprocessor could be made to indicate > > what G level should be pulled for every flight condition... > > > > Al Bowers > > > > -- > > Al Bowers > > bowers@orville.dfrc.nasa.gov > > |
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