airxliban
Posts: 4285
Joined: Wed Oct 01, 2003 12:14 pm

What Engine Designs?

Sun Nov 09, 2003 8:16 am

I have always wondered why engines look different. Some have the long cylindrical look while others have that cone in the end. Does anyone know the difference? This is what i mean...

Have a look at the GE90 with the "cones":


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Photo © Damiano GUALDONI



And the RB211 with the cylindrical look:


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Photo © Gary Watt



And KLM's 744 engines, I think they are GE's and they have a little funnel but no cone?


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Photo © Ritsaart Kreiken



Any ideas?
PARIS, FRANCE...THE BEIRUT OF EUROPE.
 
Fred1982
Posts: 16
Joined: Thu Sep 27, 2001 9:18 am

RE: What Engine Designs?

Sun Nov 09, 2003 8:49 am

The GE 90 engine with the cone uses that cone to straighten and smooth the exhaust gases to extract the greatest possible thrust. The RB211 uses a intergrated nozzle which mixes the exhaust gases and fan bypass air prior to exit from the engine. This helps to reduce noise. As far as the GE engines on the 747 I believe those are the CF-6's. Those have a smaller cone inside of the exhaust nozzle which does not extend beyond the end of the nozzle. I went to school for an aircraft mechanic still working on getting my license's only have to take my Oral and Practical. More to come when I look into my books on this. Fred
 
BA
Posts: 10134
Joined: Fri May 19, 2000 11:06 am

RE: What Engine Designs?

Sun Nov 09, 2003 9:02 am

It all has to do with different methods of thrust that come out of the back. Engines with these different designs are high-bypass engines which means the engine creates most of its thrust from a large fan located in the front that is connected by a shaft from the turbine.

Fred explained them to you pretty well.

Also, all of the 777 engines have the cone design. The Pratt & Whitney PW4000s are pictured below:

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Photo © Daniel Alaerts



Below are the Rolls-Royce Trent 800s:

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Photo © Konstantin Von Wedelstaedt



Regards
"Generosity is giving more than you can, and pride is taking less than you need." - Khalil Gibran
 
airxliban
Posts: 4285
Joined: Wed Oct 01, 2003 12:14 pm

RE: What Engine Designs?

Sun Nov 09, 2003 11:02 am

thanks for the responses. i figured it must be something to do with the way thrust is expelled.

Air Liban
PARIS, FRANCE...THE BEIRUT OF EUROPE.