Triple Spoole vs Twin Spool?!
Thread Starter
Joined: Apr 2002
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From: Usually Somewhere Else
Triple Spoole vs Twin Spool?!
Hi all,
Just wondering if anyine can definitively answer this: What is the advantage of a triple spool engine as opposed to a more standard twin spool. I have heard all of the arguements; more efficient, quieter, more rigid therefore less wear etc, but am woning why (if it is) more efficiant.
Cheers,
All the best
Just wondering if anyine can definitively answer this: What is the advantage of a triple spool engine as opposed to a more standard twin spool. I have heard all of the arguements; more efficient, quieter, more rigid therefore less wear etc, but am woning why (if it is) more efficiant.
Cheers,
All the best
Joined: Apr 2005
Posts: 201
Likes: 0
From: Uk
Any spool has its optimum speed it can operate. So with a single spool , this speed is not the most optimum for each stage of the compressor and turbine , so by adding more spools more stages can operate closer to the optimum.
A triple spool willl have more stages operating at their optimum speed than with a twin spool and as a result can be more efficient, however there is a weight offset by having the extra spool and it also can make the engine a little more complicated.
I could get into blade tip speeds etc etc but thats the general idea.
A triple spool willl have more stages operating at their optimum speed than with a twin spool and as a result can be more efficient, however there is a weight offset by having the extra spool and it also can make the engine a little more complicated.
I could get into blade tip speeds etc etc but thats the general idea.
Joined: Mar 2000
Posts: 8,571
Likes: 3
From: Arizona USA
3-spool, advantages...
Fuel efficiency.
Quiet, more so generally than a 2-spool design.
Disadvantages...
More expensive (generally).
More complicated, and heavier.
The first 3-spool engine (RB.211) was used on the Lockheed TriStar, exclusively, and after a short problem start, provided superior performance...especially in the fuel consumption and noise departments.
Three spool Rollers are very good engines...the best in the business, in my humble opinion.
The Dart wasn't bad, either, although far outdated now, it also was superbly reliable.
Bar none.
If I was designing an aeroplane now, today, it would have Rollers, and nothing else.
The Brits done it right.
Fuel efficiency.
Quiet, more so generally than a 2-spool design.
Disadvantages...
More expensive (generally).
More complicated, and heavier.
The first 3-spool engine (RB.211) was used on the Lockheed TriStar, exclusively, and after a short problem start, provided superior performance...especially in the fuel consumption and noise departments.
Three spool Rollers are very good engines...the best in the business, in my humble opinion.
The Dart wasn't bad, either, although far outdated now, it also was superbly reliable.
Bar none.
If I was designing an aeroplane now, today, it would have Rollers, and nothing else.
The Brits done it right.
