Saturday, January 28, 2006
Video: Fun with Jet Engines
Every jet engine works because of Newton's third law of motion- for every action, there is an opposite but equal reaction. In your typical aircraft turbo jet engine, air is sucked in the front and roars through a set of compressor blades, increasing its pressure. Simultaneously, it mixes with fuel and ignites. The resulting combustion results in a rearward force as the products of the combustion zoom out through the exhaust nozzle. I think back in engineering school, this was called "a Brayton combustion cycle."
Like Newton says, the backwards pointing force must be balanced with an equal force that pushes the the airplane attached to the jet engine, forward. The forward force is the thrust and that propels an airplane through the air.
Take a look at what the backward force can do:
link 1 http://video.google.com/videoplay?docid=-1309610693318372088
link 2 http://www.nearlygood.com/video/jetblast.html