Controlling Air Flow

[Shadow]

 I think I know the answer to this but will get opinions anyway. If a fan is mounted inside an enclosure, say a 9 inch fan inside a 10 inch pipe, relying on strictly wind to turn it, can the speed of the fan be controlled by the amount of exhaust air released out the back?If only a certain amount of air behind the blades is allowed to escape, the back pressure should keep the blades at a certain speed no matter how fast the wind blows?.Thought I may save some experimenting by asking here... Thanks

[rotornuts]

Definitely. If you restrict the outflow then the less air will enter the pipe in the first place thereby controlling the speed.

Mike

[Sheogorath]

yeah, all the air that comes in has to go out, so varying either the intake or the exhaust will create a direct variation with the other.