Dynamic Soaring or DS is flying a glider in a circular path behind a slope with a sharp ridge and using the boundary layer of air between the windy and still air to gain energy as the glider passes quickly through on each circle. The speed record for this type of soaring was 498 mph in 2012, maybe it has been surpassed. Update 505 mph in 2014
My JW Glider Flown by Pat Bowman in DS Circuit |
On several slope soaring trips I was able to observe dynamic soaring and one day was able to successfully fly some DS circuits with my JW glider. In the video embedded in this article you see Pat Bowman who sold the JW glider through his company flying my JW through some DS circuits. Pat made it look easy but I found it stressful but fun. For whatever reasons I was away from slope soaring of any kind for several years until a couple years ago I was slope soaring from smaller hills closer to where I lived.
Some of these small hills had slopes on both sides and I tried making some DS circuits without any luck. After a sharp turn at the bottom of the circuit, the glider just lost all the energy to keep coming back up. One of these slopes had a flat road on top which I found out reduces the efficiency for DS. I kept practicing trying to make circuits on the back side of the hill, just to get more comfortable with diving the glider over the backside of the hill. I even tried electric gliders and adding power to make the circuit upwards along the backside.
The Ridge I Used for DS |
There was another hill that had a sharper ridge on the top and I thought with a more efficient glider it should be possible to make some DS laps. Finally a week ago everything came together, the wind was coming into the hill fairly straight and I had a DLG glider that was much more efficient than my foamie gliders. First I started on a lower portion of the ridge making circuits around the backside of the hill and out into the wind, just to get more comfortable with the process.
The Backside of the Slope |
Soon I moved to the highest part of the ridge and went for making more than a single DS circuit. After getting the glider fairly high on the windy side, I dived it across the top of the ridge down along the backside. This time I did not pull it back as quick as normal but did more of a round circle and the glider came back up the hill shooting upwards with speed. I pulled on the elevator and sent it diving down the backside again; I was really doing the DS circuits now. After a few circuits I let the glider fly over to the wind side maybe I could have kept going but I needed to calm my nerves.
Flying Super Scooter on Front Side Earlier |
In the current issue of Model Aviation magazine is an article in the Sky's the Limit column by Jennifer Lilley, “The Magic of Body English for Flight Perfection”. Maybe that was why I was successful with the dynamic soaring this time because I was really into the body English on each lap of DS. I was able to repeat doing several laps a couple of more times and then quit because it was starting to get dark and my glider was still unbroken. What a thrill!
Dynamic Soaring Weekend about my next chance to try DS
Bill Kuhl
http://www.ideas-inspire.com
2003 Video of DS Flying
Dynamic Soaring technique by Glidingvideo
Blogger eats comments sometimes but I'm trying again. I came here after seeing your post at RC Groups.
ReplyDeleteThanks for checking it out, I had another chance to try DS before snow covered the ground http://scienceguyorg.blogspot.com/2014/11/dynamic-soaring-weekend.html
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