Dave Yost
rrAdvertiser
Location: San Diego Ca, USA
My Posts This: Topic Forum | | Quote |
| if TST is such a great idea, don't you think every full scale military heli and jet fighter for that matter would have dimpled rotors and wings, and while we're at it, wouldn't every car is this fuel and oil oppressed world have it too. no, and by the way it has been tried, i have pictures of some of them, i think its another marketing ploy to get everyones " what if" factor up.
|
It has to do with the size of the airfoil in relation to speed and viscosity. So in most cases, a jet fighter or even a full scale rotor would not benefit. However, You guys are missing a key point, the cord of an RC helicopter blade is much smaller in relation to the air monocles. Full scale helicopter aerodynamics dose not apply here. You must first apply the Reynolds equation to see what range you are operating in.
Air monocles expand and contract with changes in temperature. But the difference between one extreme and another, say 28.00Hg and 31.00Hg is not that significant if your using a very small airfoil.
This is why if you scale down a war bird, like a P51, they fly much better if you change the air foil.
I am way, way to busy to get into this at the moment, but here's the steps I would take:
1. figure the tip speed at 2000 RPM
2. Apply: Re=(Density/Viscosity)X Velocity(at the tip)X Length(tip cord I think)
If Re= less than 300,000 or so, the tip is operating in turbulent, non-laminar airflow and will benefit from boundary layer enhancement.
see the following ref.
Theory of Flight, Richard Von Mises, Page 167, influence of Reynolds numbers
Model Aircraft Aerodynamics, Martin Simons, page 33
Aerodynamics for Naval Aviators, H.H. Hurt,Jr, Page 54,55
I am NOT sponsored by Vblades, but I have watched Alan and Danny fly both, and I can tell you there is less bogging and less noise which must mean a lower coefficient of drag.
Dave
MA Fury Extreme,Vibe 50, JR 9303,YS,Vblades, Don't blame me, I voted for Jimmy Buffet! |
