Sadly, with the current rate of progress the CJ2000A won't make the C929's FF (but by the time the 929's fully ready it might be ready as an option).
The auxiliary gearbox? Cause the CJ2000 ain't a GTF...
Chinese Engine Development
- Thread starter jackbh
- Start date
It was a historical weakpoint because of weak materials and weak precision manufacturing. The same technical competences that go into advanced turbofans also apply to gearboxes. They’re all mech E capabilities that involve the same performance determining factors.
I thought CJ-2K is going to be a GTF to be able to compete with Ultrafan? Difficult to see how it's going to match Ultrafan's efficiency otherwise.
It's not clear that this is the direction they are committed to. They definitely seemed to have explored GTF as an option but may not be adopting it for at least the initial production design.
Hell nah, the 2kA's meant to be a GEnX competitior...
Pretty much the same architecture as the GEnX. Currently the LP spool is pretty much the same in terms of philosophy.
Indeed a GTF architecture was initially considered. But they've decided to go non-GTF. Perhaps saving it for their actual GE9X/Ultrafan competitor.
So for the foreseeable future, Chinese high bypass turbofan is going to stay one generation behind the west? Very unfortunate if true.
I mean from the announced 35.2 tf produced on-bench it should've been clear that the 2kA wasn't meant to compete with in the class of GE9X/Ultrafan...
GTFs have not yet been adopted on any engines of that thrust class.
Ultrafan is not a GE9X competitor, it's CJ-1000A and CJ-2000's direct competitor. RR is building two derivatives of the Ultrafan demonstrator, one in the 130kN thrust range for narrow body and a ~340kN variant for wide body airliners.
iirc RR said last year that they were looking to complete prototypes of both versions by 2028 and flight tests late this decade. If CJ-2000 follows the 2030 schedule it could probably get certified before it but RR will be close behind.
Though apparently you can possibly get close to the Ultrafan without using a GTF architecture. Original plans for Advance3 called for 20 percent efficiency improvement over first generation Trent with a bypass ratio of 11 and 60 OPR. Ultrafan uses the same core but combined with a geared fan for a bypass ratio of 14-15 and 25 percent efficiency improvement. Relative difference is really only ~4 percent and given CJ-2K's design is probably a bit newer than Advance3 they could probably squeeze a tiny bit more out of it.
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Without a hard delivery to production, which would require committed orders, I don't think we can really say the projected lead is that meaningful.
There are lots of different paths to improve fuel efficiency. Remember the point I keep harping about how all performance margins for jet engines start with the compressor.