Forum: F-35 Lightning II

http://www.youtube.com/watch?v=DKevRqZGoMo

"Take a quick tour of the F136, and discover the innovative, high-technology features the GE Rolls-Royce Fighter Engine Team is bringing to the Joint Strike Fighter program."

F-16.net Sponsor

I haven't heard anything coming out of the UK about the expected cancellation of the GE/RR F136??? Doesn't sound like they are to up-set??? Especially, considering the UK would gain jobs by its selection vs the all American P & W F135.

Where's the "high technology"? Blisks, Lamilloy and 3D aero have been around for well over a decade. PHM is nice, but not sure its got anything beyond the F135. All in all, a nice job by NBC, though. (P.S. I'm pretty sure the stage count in the video is wrong).

Actually the UK side of the F136 just got funded by their MoD to the order of 500M pounds (don't know how to do the goofy L).

Motorman, in all likelihood, the "high technology" is at the very least export controlled or very most highly classified. Either way, it can't be released to the public. Same goes for the F135. I'll take a look at the stage count when I get home, I've worked on the engine a little.

Ok, now that I've seen the video I can tell you it's very heavily cleaned up for public release and that's about it. I won't comment on specifics, but its only marginally accurate.

LordOfBunnies wrote:

Ok, now that I've seen the video I can tell you it's very heavily cleaned up for public release and that's about it. I won't comment on specifics, but its only marginally accurate.

A "marginally accurate" marketing video made to sell expensive systems. Who would have thought? Laughing

A few things worth noting in the video.

(1) The combustor appears to be of the TAPS (Twin Annular Pre-Swirl) design. This is also being used in the Boeing 787's GEnx engine. From a combustion efficiency standpoint this is probably the most advanced and most efficient combustor.

(2) The F-136 has on less compressor stage compared to the F135 (5 vs 6-stages). This means that stage loading is higher. Assuming that there is no loss in efficiency, it means that GE compressor technology is probably also slightly better than PW.

(3) The swept fan and hub cone looks to be more of a Rolls-Royce style than something akinned to GE's previous designs (F404/F414/F110).

dwightlooi wrote:

(2) The F-136 has on less compressor stage compared to the F135 (5 vs 6-stages). This means that stage loading is higher. Assuming that there is no loss in efficiency, it means that GE compressor technology is probably also slightly better than PW.

OR...

Consider the F135 may have a higher OPR than the F136 like the F100 does over F110. Which could account for the extra stage of compression.

F100-PW-229 OPR = 32.4/1 (Fan stages 3, Core stages 10)
F110-GE-129 OPR = 30.7/1 (Fan stages 3, Core stages 9)

J@nE'$ states the F135 has an OPR of 35 and the F136 has an OPR of "35+" Knowing the F100-PW-232 had an OPR of 35, and the F119's OPR is "in the 35:1 class" I would think the F135s may be a little higher... Two Cents

I guess declassification and admission by the OEMs will be the final word.

EDIT: (Added thought)

An OPR of 35/1 may have been a requirement of the engine contract for the JSF or F-35 program. Shrug

Keep 'em flyin' Thumb

TEG

I tend to be highly skeptical with regard to any technology or performance claims being touted by GE/Rolls-Royce with regard to the F136. It's easy to make a wide assortment of claims when you're nowhere near a production ready standard. Paper engines can do almost anything. It's quite another to deliver when the tires leave the asphalt.

The F135 has surpassed 12,000 engine operating hours under its System Development and Demonstration (SDD) test program, and accumulated an additional 3,600 hours of engine tests during its Concept Demonstration Phase (CDP). The first seven production-standard F135 engines are due for delivery by the end of 2009.
http://www.pw.utc.com/vgn-ext-templatin ... mt=default

The first "new build" F136 engine, on the other hand, didn't even enter testing until late this past January - and then had to shut down four weeks later due to a bearing problem. Testing only resumed again this past May.
http://www.flightglobal.com/articles/20 ... ng-in.html

Prior to this year's first SDD engine test, the F136 had accumulated just over 800 hours of testing under two prototype engines - which incorporated a combination of "new build" components, together with hardware that was acknowledged to be non-representative of the anticipated production configuration.
http://www.geaviation.com/aboutgeae/pre ... 90202.html

The bottom line is that the F136 has a very long road of testing and redesign ahead of it, before it could be considered anywhere near a production-ready standard. I have every confidence that the GE/Rolls-Royce team could overcome the technical hurdles and difficulties that are part of a normal development process, given sufficient time and budget. Unfortunately, under the current state of the economy, that additional budget is a luxury that not everyone is convinced that we can afford.

That_Engine_Guy wrote:

J@nE'$ states the F135 has an OPR of 35 and the F136 has an OPR of "35+" Knowing the F100-PW-232 had an OPR of 35, and the F119's OPR is "in the 35:1 class" I would think the F135s may be a little higher... Two Cents

I guess declassification and admission by the OEMs will be the final word.

An OPR of 35/1 may have been a requirement of the engine contract for the JSF or F-35 program. Shrug

Keep 'em flyin' Thumb

TEG

The overall pressure ratio of the F135 is 28. See...

http://www.f135engine.com/proven-tech/engine_chacter.shtml

This however doesn't mean that the compressor pressure ratio is lower than engines like the F100.

The contra-rotating rear section is pretty interesting. Its a pity there wasn't a cut-away of the AB section.

I've been wondering, the EJ200 doesn't possess VIGV's, what ar the tradeoffs in such a design?

Obi

Obi_Offiah wrote:

The contra-rotating rear section is pretty interesting. Its a pity there wasn't a cut-away of the AB section.

I've been wondering, the EJ200 doesn't possess VIGV's, what ar the tradeoffs in such a design?

Obi

The F135 is contra-rotating too. As is the GEnx engine to power the Boeing 787.

dwightlooi wrote:

Obi_Offiah wrote:

The contra-rotating rear section is pretty interesting. Its a pity there wasn't a cut-away of the AB section.

I've been wondering, the EJ200 doesn't possess VIGV's, what ar the tradeoffs in such a design?

Obi

The F135 is contra-rotating too. As is the GEnx engine to power the Boeing 787.

So are the F119 and F135 Cool

TEG

As I've stated before, GE and Rolls don't particularly like each other on this project because they've got to deal with each others best practices and having to interface parts. Either would love to buy the other out of the project I'm sure (I know this in the case of GE).

There's a reason you don't see anything about the afterburners, usually any significant afterburner data is classified a minimum of secret if not top secret. This is because it's such a large part of the thermal signature of the aircraft.

TAPS is GE's new baby. They're converting everything that can to TAPS because it provides some environmental benefits and some small performance benefits over their normal combustors. There were a few ideas they were kicking around that was one they came out of the process with.

VIGVs allow you to line the flow up with the first stage of rotor meaning you can design them to get more pressure out of them. The drawback is that it adds weight. Any time something moves, weight is added.

I may see some of the backlash from the funding cut of the F136. GE ships a fair bit of work over to Belcan (where I am), and with a funding cut they may pull some of their projects back in house and we'll lose work. They'll shift people around if the funding really is dead, that way if some of their other engine bids come through they won't have to lay people off.

dwightlooi wrote:

The F135 is contra-rotating too. As is the GEnx engine to power the Boeing 787.

That_Engine_Guy wrote:

So are the F119 and F135 Cool

TEG

Sorry, I should have been clearer. The fact that the F136 doesn't have stators between the high and low pressure turbine is the interesting bit. It reminds me of SNECMA's contra-rotating turbofan engine, albeit the latter is alot more complex.

Obi

Forum: F-35 Lightning II

F136 Utube inner workings video