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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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