Although an axial compressor has a few things in common with a window fan, the analogy is pretty wide of the mark.
A jet engine is a gas turbine. How does that gas turbine get the compressed air it needs to operate? It drives a shaft coupled to a compressor. Most compressors used to be centrifugal types, but now they're almost exclusively axial. If you want to know how an axial compressor works, do a Google search on "how does an axial compressor work".
In fact, if you want to know anything, do a Google search on it and click on the Wikipedia entry. There you are bound to find what you're looking for and you won't get a lot of guesses about blades window fan beating the air.
As far as the gas escaping the "wrong" way, that's exactly what happens during a compressor stall. Axial compressors rely on the orderly flow of air from front to back. High efficiency compressors are not far from disaster much of the time and dirty blades, a bad fuel control unit, damage to the blades, or simply feeding air into the inlet other than head-on can produce a compressor stall.
I used to fly a high performance fighter and, as all of us who understand what pushing the envelop really means, I have a little bit of high speed flight time traveling backwards with fire shooting out of the intake. The old J-57 was not prone to compressor stall most of the time, but it certainly didn't take kindly to going backwards at speeds.
Last edited by Mozella; 23rd May 2014 at 03:32.