Forum: Technology

It seems like every country outside of the US, Britain and Russia cannot really get a grasp on jet engine technology. China has a good technological base, bought Russian technology, stole more Russian technology and put a great deal of time and effort into the WS 10 and yet the program still flopped. India has spent over a decade attempting to devolop the Kaveri engine and the program hasn't really seemed to go anywhere.

In contrast to engines, it seems like nobody has problems producing the other parts of a fighter aircraft. Even low tech countries like Israel and Pakistan have been able to build bonafide 4th gen airframes and avionics systems.

So why are engines such a bottleneck?

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Experience.

Besides the patents on how specific engine components function, basic internal principles, or design concept; jet engines include copyrighted metal alloys, copyrighted 'processes', and copyrighted coatings, among other things.

Even if you had an example of a modern military aviation gas turbine engine, it is impossible to completely backwards-engineer all the fine points.

How were the metals in the alloy combined? How is it cast? How is it forged/machined? Is is stress-relieved or heat treated? What coating is applied? In what thickness is the coating applied? How is it bonded to the base metal?

Things as simple as pouring metal into a mold in a specific manor, direction, or rate can completely change the longevity and/or reliability of a turbine blade.

Just about anyone could produce a jet engine in a machine shop given the proper tools and equipment, but will it have a 10/1 Thrust-to-Weight ratio? Produce 35,000lbs of thrust in MAX-AB? Have a 6000+ cycle life? Start every time and continue to run even after absorbing battle damage? Can it be mass produced at acceptable cost? Hardly.

Keep 'em flyin' Thumb

TEG

The above mentioned nations who've mastered production high-end fighter engines are actually using very small amounts of metal salvaged from alien spacecraft that crashed in America and Russia during the 1940s and 1950s. Supply has been managed through minimal use and careful recycling, which is why everyone was so upset when Israel lost a worn-out F-15 engine a few months back. Wink

Thank you for your reply

Besides the patents on how specific engine components function, basic internal principles, or design concept; jet engines include copyrighted metal alloys, copyrighted 'processes', and copyrighted coatings, among other things.

But China and Russia don't honor US patents. In fact, I'm not sure China honors patents period.

Just about anyone could produce a jet engine in a machine shop given the proper tools and equipment, but will it have a 10/1 Thrust-to-Weight ratio? Produce 35,000lbs of thrust in MAX-AB? Have a 6000+ cycle life? Start every time and continue to run even after absorbing battle damage? Can it be mass produced at acceptable cost? Hardly.

Well China appears to be incapable of of even building engines that were as good as we had on the original F-16's.

First off Russian engines don't last but about 1/4 to 1/3 TBO of western engines.

As for the patents, think of this example (See photo below)

Sure you have a diagram from a patent, but no specifics:

Can you answer any of these questions if you took the patent right from the patent office?
EDIT: or found all these patents/diagrams online? Even NASA reports on turbine engine experiments over the last 4 or 5 decades?

Shrug

TEG

TEG, I'm curious what your critical assessment might be of the latest RD-33MK variant in particular, intended for the Mig-35? It's reported service life is apparently 4,000 hrs and it would appear to be a credible advancement in engine technology and performance. TIA.

Flight Global wrote:

The current production-standard RD-33MK selected for Indian navy MiG-29K/KUBs develops 20,000lb of thrust and has a 1,000h TBO

http://www.flightglobal.com/articles/20 ... ussia.html

Consider the lowest module TBO on the PW-229 is almost twice that (For the Gearbox Module of the Viper, Eagles get more time than that.) The other 4 major modules currently serving in the PW-229 are rated for 4300 "Total Accumulated Cycle" a.k.a. TAC.

New production PW-229EEP engines are rated to 6K TAC!

PW White Paper wrote:

Incorporation of the F100-PW-229 EEP — successfully demonstrated in 2004 — achieves the objective of increasing the engine depot inspection interval from 4300 to 6000 TAC. This increase is equivalent to extending the depot interval from seven years to ten years. In addition, the EEP provides a 30 percent life cycle cost reduction over the life of an F100-PW-229 engine.

(The PW-229EEP has been infused with a bit of F119/F135 tech by PW Wink

)

The other thing to note is "reported service life is apparently 4,000 hrs"; which means after roughly 4 overhauls, throw the engine away.

The F100/F110s on the other hand have been overhauled for decades. The PW-100s were finally removed from their final active service just a year or so ago. They do live on (for a bit) in the PW-100D - upgraded to 'D' standard for use in the QF-16 Drone program. (A, B, C were taken, D was next but does fit nicely for drone) While the PW-220(E) were removed from Vipers going to AMARC, the PW-100s were retired from service and placed into the retired Viper airframes. Just in the last month I touched a motor that started PW0E68xxxx. She had been a PW-100 upgraded to a PW-220E and is still in active service; overhauled many MANY times (likely more than 4x) since her introduction decades ago.

Meanwhile our Russian jet engine brothers are bragging about 1K hour TBOs and 4K Hour service lives? They may be cheaper up front, and cheaper to repair for the first decade, but how many replacement engines do you have to buy to keep your fleet flying after 30-40 years like the USAF Eagles?

Poke

TEG

Ok, thanks for that input... TEG buddy. Good points Not Worthy

I was just looking for a point of view on this one from someone in the business. One could conclude it will ultimately come down to a particular customer's usage doctrine then, or to effective marketing, to justify either one system over the other..

Forum: Technology

What makes engines so hard to make?