Originally Posted by
james ozzie
We all once sat in a classroom and learned that a rocket engine is a reaction motor, relying on the reaction of expelled exhaust mass to create an opposite reaction force (Newton 2). We also learned that a turbine creates thrust in exactly the same way (reaction from exhaust action).
Not quite. The wikipedia definition of
rocket engine is helpful.
Rocket engines take their reaction mass from within the vehicle and form it into a high speed jet, obtaining thrust in accordance with Newton's third law. (ny
bold)
A turbojet or turbofan starts by sucking in a great deal of the reaction mass it pushes out the back. Thus it's different to a rocket.