Subject: How does a funnel affect the force of wind?

What would happen to a 60 MPH wind that entered a rudimentary funnel of some 4 
meters in length via an entrance of say 1 square meter and exited through an 
exit of maybe .25 square meters? I'm interested in what happens to the 
pressure, speed, and the force of the wind as well as how much wind simply 
bypasses the structure. Also, I'd like to know if there is something 
approaching an ideal ratio of entrance area, to exit area, to length for 
maximum output force. Any other info or useful formulas for compressible fluids 
would be greatly appreciated.

Re: How does a funnel affect the force of wind?