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Archive for November, 2012
Posted by phil alvirez | Nov 20, 2012 @ 04:04 PM | 5,660 Views
Thermalis is an idea of an electric sailplane for soaring in calm to moderate wind. it has 80" wingspan and 10" chord almost to the tip, and 764 sq in; weighs 926 grams (32.5 oz) with a 3x1400 mah pack. i just started evaluating it and will provide comments whenever i get enough flights, but so far am flying in cold weather with no thermals. am also playing with cg and trim.
nov 21-the concept: a simple sailplane for rudder and elevator-no ailerons, for relaxed flying and getting into thermals (hence the name), in moderate wind conditions. the wing is 1 piece polyhedral and the fuselage is box type, 1/8" solid balsa, like the horizontal tail and rudder. still, as i wanted to try spoilers and flaps for the 1st time, i decided to add them. the flaps are of the split type (similar to the 1s used on the full size douglas dc-3). another feature that i added was the t tail, that is not as simple as conventional tail, i must admit (i will comment on this later).
>>>will be adding details. check at the bottom.
testing the Thermalis‏
21/11/2012
i started with the cg a little bit forward from the point for which i designed it. the launching went fine, with a strong climb at half throttle. the motor is very powerful and with the 10/6 folder it has lots of power. the climb is at about 70-80 degrees without tendency to tip stall, that was haunting me with the other sailplanes before. the glide is the best i have got compared with the other...Continue Reading
Posted by phil alvirez | Nov 15, 2012 @ 12:19 AM | 5,497 Views
at the beginning i posted a link to an article where it stated that thermals are like horizontal donuts that climb, with the wind going up at the center and down at the edges.
we all believed that article (it was back in the 60's), but recently i found another approach. http://www.xcmag.com/2007/07/thermal...rt-1-thermals/ where he brings an explanation that comes very close to how cumulus nimbus grow, including the same shape, so am beginning to lean towards this idea.
so this way thermals don't turn left or right, just wind goes up inside and down outside-and this matches with the other theory in that sense, so you turn any way you find is better to stay put.
and the idea of trimming the planes to glide to the left from those days could be to balance the torque of the motor, be rubber bands or engine-and somehow it became customary and we did gliders that way too. just a guess.
Posted by phil alvirez | Nov 02, 2012 @ 06:02 AM | 5,524 Views
on shape of thermals



i found this, providing data regarding the shape of thermals:

http://www.xcmag.com/2007/07/thermal...rt-1-thermals/

which looks very much the way cumulus nimbus behave.

by the way, i just started a thread in the forum "thermal":
http://www.rcgroups.com/thermal-36/
and still another view:
http://www.soartech-aero.com/Thermals.htm
and 1 more: http://www.rcgroups.com/forums/showt...64#post4966743