YOU PEOPLE

4/13/2009 4:43:32 PM

Quote :

"are you guys assuming that the treadmill will move the wheels of the plane forward, but the plane stays still (if the plane was powered off)...so no friction between wheels and plane?"

That's how I prefer to explain it for the first time through. Afterwards I qualify it by saying that there is indeed a little bit of friction but it's not enough to make a big difference.

Quote :

"well, the treadmill could also move the air in the region near in its direction (actually increasing the airspeed at the wings) which might actually decrease the power required from the engine to take off."

Huge boundary layer like woah.

(I remember grading some papers (or having an office-mate grade some papers) for BL theory and laughing at some of the answers on some papers. 10m thick BL after 1m of flow along a flat plate. ha!)
(but if the treadmill is long enough, then the BL can get pretty damn big)

4/13/2009 5:03:04 PM

(i understand bl theory todd, i'm just saying that if anything, the treadmill may improve performance of the airplane)

4/13/2009 5:04:26 PM

There is no treadmill, only Zoul

4/13/2009 5:07:30 PM

lift depends on airspeed not ground speed. plane takes off.

4/13/2009 5:45:24 PM

You probably know more BL theory than I do, John. Just making a bit of a joke. For the BL to get large enough to help out the airflow would be pretty much like woah. But indeed possible if the treadmill's big enough, like you said.

4/13/2009 6:02:27 PM

Now that it's going to be resolved, the plane will take off. Given that the force of the propellers pushing on the air is greater than the opposing force coming though the rolling friction of the wheels on the conveyor by enough to accelerate the plane up to take off speed. which it should be because the rolling resistance of the wheels is hardly anything, and once it gets them spinning, only its increase in speed would even push on the plane at all.

4/13/2009 6:03:00 PM

[NEW]

4/13/2009 6:06:33 PM

Did it take off, or not? I'm not looking through 14 pages to find out.

4/13/2009 6:28:17 PM

Quote :

"There is no treadmill, only Zoul"

I believe, sir, that you are referring to "Zuul".

4/13/2009 6:31:13 PM

yes it took off. [/thread] for the 10th time in this thread.

4/13/2009 7:03:10 PM

♥

4/13/2009 7:05:23 PM

Quote :

"10m thick BL after 1m of flow along a flat plate. ha!"

Haha was DeJarnette the professor for that section? Because if he was, I can understand how some students might think a 10m boundary layer is a common thing.

4/14/2009 4:50:29 PM