alloy_skydragon
27th Apr 2002, 06:20
What are the types of engines and how do they function? I've heard of clam shell engines, and bucket engines (or something like that) but have no clue as to what they are. Also, what type do you think would be on a Boeing 737-300? Does it matter?
OK! Sorry for all the questions, if anyone can answer them I would really appriciate (sorry, not a good speller :rolleyes: ) thier help! Thank you!:D
Flight Detent
27th Apr 2002, 10:50
Hi Alloy,
Sounds like you are referring to engine reverser types, not actual engine types!
Modern jet engines are basically all the same, the 'core', or actual engine, develops around 25% of the total engine thrust, with the fan developing the remaining 75%.
The 'fan' is that large enclosed fan you can see in the front of the engine, (it's actually just a fixed pitch propellor), most of it's thrust just bypasses the core engine, around the outside, known as the coldstream duct, and on out the rear, totally surrounding the core engine's thrust stream, and thus making the "Hi-bypass" engines much quieter.
In the good old days, with the B727s and DC9s, they did not use hi-bypass engines, hence they are much louder, and they used external 'doors', located in the exhaust stream at the rear of the engine, to redirect the exhaust forward, on the ground, to help slow the aircraft after landing.
They were referred to as 'buckets' and 'clam shell' etc.
In hi-bypass engines, only the coldstream thrust is redirected forward, by some doors closing the normal path, and at the same time, the rear part of the each side of the engine cowl slides aft, and the redirected cold air is thrust forward, slowing the aircraft , only on the ground.
Sorry for the over-simplification, hope you understand.
Cheers