Feb 12, 2013, 11:23 PM
|
|
|
Midvale, Utah, USA
Joined Mar 2005
6,946 Posts
|
Quote:
Originally Posted by Bloosee
That has had me scratching my head for a while about this plane, it seems like most of the thrust from the prop will just be blasted straight into the cowl, yet this is a very fast "race" plane, its just odd how that works. I'm trying to think back to my engineering school days for an answer and can't come up with it
I'm sure TurboParker can school us on this....
|
Quote:
Originally Posted by bhoov128
Propeller blades are airfoils themselves. They aren't very efficient blowing all kinds of air back into the cowl, but they do in fact create low pressure in front of the blades and considerable suction through the air. The original Gee Bee worked just fine with a prop that didn't clear the cowl very much 
|
yea the airfoil thing is part of it, but not entirely correct.... You cant really compare it to a wing in normal flight, its more like a wing in high alpha flight.
Liek bhoov128 said, a propeller doesn't work by "pushing air backward", it works by pushing ON the air, and "screwing" itself through the air (another name for a propeller is an airscrew)
Think about a plane in high alpha flight... its pushing a whole lot of air downward due to its wing angle, but do you think its flying because of the air its pushing downward, or the air that's pushing against the wing as the plane moves forward? Another way to look at it, ever stuck your hand out the window on the freeway? Angle it up and the air striking your palm moves it upward. (not the air that's deflecting downward)
While that big cowl does have some effect, its not as much as you would think. On the original, being able to fit that giant engine was a much bigger plus than the small negative effect of the"wall" behind the prop....
Also remember that the inner part of the prop isn't really pushing that much air...
|
|
|
|
|