Turbines question for E-2, C-2, P-3 guys...

[selmacf7]

Hey guys, I need a bit of turbine information for some Gas Turbine Course Extra Credit. Half of it (dealing with the Honeywell T55-GA-714A TS) is already taken care of, but have a few questions on the Rolls Royce T56-A-427 Turbo Prop being used in the newer E-2's, and I THINK the C-2 and P-3, though they may have older versions. I know the C-130 used an old variant of it...

What I Know:

Thrust Rating (5250 SHP)
Type (TP)
Comp. Ration (11.5)
Combustor Type (Annular)
Envelope (L,W, Weight, etc)
Uses
Blades on rotor system


What I Can't find...

Number of Spools in the Compressor
Number of Comp. Stages per spool
Type of Compressor (I think it's Axial/Centrifugal, but not sure... which would make for two spools, btw)
Number of Turbine Stages/Spool
SFC


I'm pretty sure that's all of it... Honeywell had a great website for their engines, but not so much with the RR. Appreciate any help you guys can give me.

 

[kmac]

CODs have T56A-425's. They're the older E-2 engines.
They are 14 stage compressor (axial) and 4 stage can-annular (6 cans, 2 igniters plus crossover tubes) combustion. Each is a single spool.

 

[selmacf7]

Can-annular... really? I would've thought annular. Think I was looking at specs for (what I thought was) a similar engine when I came up with that. Then again, I thought it had a centrifugal comp in there too.

 

[kmac]

No I'm making it up. And I have never seen a centrifugal compressor on here. Just the axial ones.

 

[selmacf7]

Cool... so who's got a number for Spec. Fuel Consumption?

 

[zab1001]

if I knew what Spec fuel consumption was, i'd tell you.

(all i know from is the T-56-14 and T-56-10)

 

[ChuckMK23]

No I'm making it up. And I have never seen a centrifugal compressor on here. Just the axial ones.

Centrifugal compressors are big in helo power plants - Rolls Royce (nee Allison) 250 Series (TH-57), LTS-101 (HH-65, AS-350D, M1 Abrahms Tank)

 

[Pags]

Cool... so who's got a number for Spec. Fuel Consumption?

You're not gonna find a SFC number in any manuals, that's an engineering number.

 

[selmacf7]

Yea... SFC is kind of a hard thing to find, though not THAT hard.... I'm sure an hour in the library would take care of it, but who wants to do that?

There are a couple of TP's with centrifugal comps in them... PT6A has one in it , AKA T-74-CP-701. Guess it was used as both a TP and TS.... Modern Cent compressors have gotten pretty good, not uncommon in TP's.

Aaaaanyway, I'll hit up the library tomorrow and see if I can find SFC... need to confirm my other stuff anyway. Thanks for the help.

(feel free to add more, of course)

 

[Steve Wilkins]

http://www.rolls-royce.com/defence_aerospace/downloads/tactical/t56_a427.pdf

 

[selmacf7]

Perfect... don't know how I missed that on the site. Think I was looking in the downloads section.

In retrospect, single spool and axial flow make sense... single shaft = quicker spool up = not hit the back of the boat, or so goes my logic.

 

[Pags]

Centrifugal is better for smaller engines. The PT6 family of engines has both a cent. and an axial section (and wasn't originally designed as a/c powerplant). Larger engines are gonna be axial because you can get a higher compression ratio due the multiple stages. It's pretty hard to get an efficient multiple staged cent. flow engine.

 

[FLY_USMC]

J69-T-25 is a single stage centrifugal compressor engine that's used in the T-37B Tweet.

 

[Pags]

Probably because that engine predates the idea of axial compressors

 

[highlyrandom]

don't you just divide fuel consumption in lb/hr by thrust horsepower?


Never mind.