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Thread: Stall Speed
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Old 04-27-2011, 05:38 PM
  #19  
Rick.
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Default RE: Stall Speed

The best way to estimate your models minimum speed before the increasing angle of attack stalls the wing is to FLY it, slow it down at a safe height and let it stall - you can then SEE how fast its flying for this to happen. You'll find things simply do not work according to the number crunching, for example, despite the washout, that narrow wing tip may just decide to stall on one side, well before a nice clean straight stall can develop, if it does that'll chuck all the carefully crafted math out of the window.

Don't get me wrong, the math IS fun, I calculate my models expected stall speeds (or more correctly speed at the stalling angle of attack) just to get an idea of it, but for flying models with low Re and the unpredictable effects of gusts cross winds and even low level windshear, the math will not tell you how to fly. I assume that as this is an ambitious large model compared to typical sunday club flyers machines, you must be a well experienced model flyer already - in which case you'll already know that calculating a theoretical stall speed ain;t gonna count for anything when your out on the grass strip flying the maiden by the seat of your pants.

It does look like its shaping into an impressiive plane and when its ready for flight it would be great to see some pics of it in action. Good luck and don't worry too much about the numbers

Oh, one final thing - what are you powering it with - i guess its too big for electric, so is it glow DF or are we talking real jet turbine????