Turbines, Turbofans, Turboprops, oh my!

[eriknorth]

I'm having a hard time understanding the difference in engine types. I hear people talking about them, but sometimes I just get confused. Could someone simplify for me how turbine, turbofan, turbojet, and turboprop are related?

 

[banned username 2]

I'm having a hard time understanding the difference in engine types. I hear people talking about them, but sometimes I just get confused. Could someone simplify for me how turbine, turbofan, turbojet, and turboprop are related?

A Turbine is anything that uses a Gas Turbine for power (all of the above listed engines)

A Turbo-Fan is a Jet engine with a fan on the front, it is the most common "Jet" engine of today... 747, 757, 767, 777, Falcons, G-IV/V, Lear 30, 50 and 60 series, Citations, etc... all have turbo-fans (Hi-Bypass at that)... There is hi-bypass and low-bypass turbofans... low bypass are older and hi-bypass are newer and more efficient. A hi-bypass turbofan produces a large percentage of its thrust from the fan, and a small percentage of thrust for the jet core of the engine... A low bypass engine develops a smaller percentage from the fan and a larger percentage from the core (relatively speaking).

A turbo-jet is a straight jet engine (no fan) and it produces all of its thrust from the jet core... These were the original jet engines, old airliners and old corporate jets had these (707, Lear 20 series, Hawker 125's with Viper engines) They are loud and not very fuel efficient.

A Turbo-Prop is a small turbine engine that has a gearbox that converts the power of the turbine to a shaft which turns a propeller. These turbine engines are small and fuel efficient, the power produced is more efficient urning the prop than creating thrust from the small jet core.

Hope this answers your questions...

 

[Flymach2]

Hi...

In addition to the above post check out this link.....it may help clear a few things up for you.

Regards


Gas Turbine Engines

 

[chawbein]

NASA has a pretty good explanation and graphics at this site.

Beginner's Guide To Propulsion

Also, you might think about buying a book. I got one that was fairly elementary called Jet Engines: Fundamentals of Theory, Desing, and Operation

Hope this helped.

 

[LR25]

You know there has always has to be someone to contradict you.

Really though, the 707 and DC-9 types actually had meduim/ low bypass turbofan. Pratt & Whitney JT3's (707) and JT8's(DC-9).

I believe there was an engine on some 707's and DC-8's that were actuall turbojets. I think there were called Conways's, not sure which one it was, some had JT4's, which I'm not sure if that was a turbojet either.

But like I said, I aint trying to bust your chops on the little stuff.

 

[chawbein]

You know there has always has to be someone to contradict you.

Really though, the 707 and DC-9 types actually had meduim/ low bypass turbofan. Pratt & Whitney JT3's (707) and JT8's(DC-9).

I believe there was an engine on some 707's and DC-8's that were actuall turbojets. I think there were called Conways's, not sure which one it was, some had JT4's, which I'm not sure if that was a turbojet either.

But like I said, I aint trying to bust your chops on the little stuff.

Make sure you push your taped glasses further up on your face while you type....

"Weeeeellll, actually the 707..." (In a very nerdly voice)

 

[100LL... Again!]

The big difference is this:

Turboprops fly at lower altitudes than jets, which causes them to pay less. If anyone could invent a real high-altutude turboprop, we could finally get regional pay where it belongs.

Turbojet engines are the preferred engine for military pilots and freight pilots in third-world countries. Also for corporate pilots who like to make noisy takeoffs.

Turbofan engines pay best and are somewhat quieter, allowing the pilots to discuss such issues as union contracts and gate agent attractiveness.

Low bypass fans are used by junior pilots until they have enough skill to handle the high bypass aircraft.

High bypass engines are larger in diameter. This originally was done to impress female passengers, but it was discovered after the fact that they were more efficient and quieter. The sad fact is that REALLY high bypass engines are essentially big ducted turboprops. No one has heart to tell this to the crews of these aircraft, however. Too cruel.

Stick with piston engines - much less confusing.

 

[busdrver]

The big difference is this:

Turboprops fly at lower altitudes than jets, which causes them to pay less. If anyone could invent a real high-altutude turboprop, we could finally get regional pay where it belongs.

Turbojet engines are the preferred engine for military pilots and freight pilots in third-world countries. Also for corporate pilots who like to make noisy takeoffs.

Turbofan engines pay best and are somewhat quieter, allowing the pilots to discuss such issues as union contracts and gate agent attractiveness.

Low bypass fans are used by junior pilots until they have enough skill to handle the high bypass aircraft.

High bypass engines are larger in diameter. This originally was done to impress female passengers, but it was discovered after the fact that they were more efficient and quieter. The sad fact is that REALLY high bypass engines are essentially big ducted turboprops. No one has heart to tell this to the crews of these aircraft, however. Too cruel.

Stick with piston engines - much less confusing.

The truth hurts.

 

[Singlecoil]

Hahaha 100LL, funny stuff.



Saab 2000? It can get up to FL310. Maybe the Bombardier Q400 can get to a similar altitude?

You would think so, but the standard version doesn't have drop down masks for pax, so it can only go to FL250, or right in the tops. Even if you pay for the drop downs, it can only go to FL270 for some reason. It'll get there in a hurry, however.

 

[100LL... Again!]

Flychicaga -

Point well taken, but it WAS satire.