![]() |
| If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|||||||
|
|
Thread Tools | Display Modes |
|
#10
|
|||
|
|||
|
Jim Macklin wrote:
If the treadmill is stationary and the belt speed is equal to the required take-off speed, the airplane will have zero airspeed if it is "moving" in relation to the belt, the airplane is moving, the prop has thrust and is balancing the rearward movement of the belt. The tires are rolling, but the airplane is stationary and there is no airspeed or lift. Let's take this to a logical extreme. The purpose of a wheel is to reduce friction, right? (Well, excluding steering and braking, since we aren't using the brakes here) Anyways, let's now assume that the airplane is sitting on the conveyor belt, and there is no friction between it and the belt. For all intents and purposes, you now have an antigravity device as your landing gear. Now run the engine up. If there is no friction between the airplane and the belt (and consequently no way to transmit force), how is the belt going to keep it stationary? Remember, sum of forces=mass*acceleration, and the sum of the forces in the horizontal plane is now mass*acceleration=thrust-drag (where drag is a function of airspeed squared). No force from the conveyor belt. Now let's put the wheels back on. Certainly, if a wheel's purpose is to try and reduce friction as much as possible, you aren't going to suddenly have some wheels that drag on you with as much thrust as your prop exerts... if it comes down to it, I'll write a Matlab simulation of this, and show the results to everyone. |
| Thread Tools | |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Passenger crash-lands plane after pilot suffers heart attack | R.L. | Piloting | 7 | May 8th 05 12:17 AM |
| Navy sues man for plane he recovered in swamp | marc | Owning | 6 | March 29th 04 01:06 AM |
| rec.aviation.aerobatics FAQ | Dr. Guenther Eichhorn | Aerobatics | 0 | October 1st 03 08:27 AM |
| rec.aviation.aerobatics FAQ | Dr. Guenther Eichhorn | Aerobatics | 0 | September 1st 03 08:27 AM |
| rec.aviation.aerobatics FAQ | Dr. Guenther Eichhorn | Aerobatics | 0 | August 1st 03 08:27 AM |