Pegasus N1 fan

[A10 Thundybox]

Should know this but don't and it's driving me nuts
Mate of mine was given part of a stator of an N1 fan from the RR Pegasus, a huge discussion then ensued about what its made of

Ally says I,
Consesnsus gernerally is its ferrous (which I doubt) 'coz it's so bloody heavy.


We then postulated that we could weigh it immerse it in water, calculate is mass/volume and then go through some old chemistry book of atmic weights and measures to find out (yawn)

I had a better idea (asking proon):cool:

Any one know?

Thundy

[airborne_artist]

Have you tried a magnet?

[ShyTorque]

Nickel alloy? It rings a bell somewhere.

[airborne_artist]

A10

PM John Farley - if he doesn't know, he'll know who does...

[kokpit]

Rotors almost certainly titanium, stators probably.

[Skycop]

As the Pegasus is a Rolls Royce engine, it is more likely that the blade is made of a "Nimonic" (TM) alloy - mainly nickel (+/- 60%) , but with some chromium, cobalt and titanium content.

RR spent a huge amount on developing this type of material for use in turbine engines and hold a number of patents. :8

[Groundgripper]

According to my 1992 copy of Janes All the World's Aircraft all the compressor blades are titanium - I presume that this includes both rotors and stators.

The turbine and stator blades are made of Nimonic alloy as this material is specifically formulated for use at very high temperatures and is not necessary for the compressor.

GG

[John Farley]

A10.

Nit pick time.

'stator of an N1 fan'

I suspect that what you have is a stator from the low pressure compressor of a Pegasus.

The term Fan (in my time) normally applied to the rotating parts of the low pressure compressor. However times change and perhaps people today treat 'Fan' and 'Low Pressure Cmpressor' as one and the same thing.

In my day the fan blades were made of titanium. I never bothered to ask what particular grade of titanium or if it was a titanium alloy. Slack of me I know - but then I was much more bothered about the effects of their shape - which went through quite a few changes to improve surge margin and reduce flutter/vibration/fatigue issues at particular RPM values.

Sorry I don't know about the stator material. Stators by definition are easier to make stay on so perhaps their material would have been a tad less high tech although the weight/strength ratio would have still been important and might still have called for a titanium based material as kokpit said.

If you really want to know the answer to your question and IF you can establish which generation of the engine your blade came from then I am sure my mates at Rolls could get you an answer.

JF

[ShyTorque]

What makes me think that it isn't titanium is the mention of it's heaviness. Titanium is a lot lighter than steel and nickel based alloys.

[ImageGear]

Had a look here ?

http://gltrs.grc.nasa.gov/reports/1999/CR-1999-209314.pdf

Imagegear

[A10 Thundybox]

Blimey!

Thanks for all of this, don't know what generation of donk so we'll leave it there I think,

Glad I can tell the MIL that it wasn't iron though, der!?

It is heavy though and is about 13 inches long most of the weight coming from a heavily splined block section on the inner end presumably this attaches to the turbine shaft and is quite a lump to deal with the forces at its anchor point

If it was made of anything else I'm sure it would be heavier but relative to its size it certainly is not light.

I particularly enjoyed MIL's face when she asked "how this chap John would know...

"Well let me see now...:E

[moggiee]

Mr Farley, sir. Might it be in inlet guide vane?

[The Rocket]

Are you sure it's a stator?

Only by the way you describe the base of the blade, and talk about it attaching to the shaft makes it sound like a rotor.

Most rotor and many turbine blades attach to the shaft using a "Fir tree root." (Looks like a fir tree, would you believe) and the way you describe the base as being "Heavily splined" sounds very much like a fir tree root.

I would not say it is a Variable Inlet Guide Vane, as at 13 inches long, it has definately come from the LP comp, and the VIGV's are situated further back, in the HP comp.

As far as I am aware, the blades are still Titanium, however, with the new mk107 engines, and the 23/45/60 blade compressors, I wouldn't like to state that as fact.

Hope this helps

The Rocket.