At this point, China's engine industry is very close to that of Russia, if not on par. The latest WS-10 variant delivers performance comparable to the Saturn 117S, the most advanced Russian turbofan currently in operation. Regarding the WS-15, the development cycle of such engines does take an extremely long time ... especially a clean sheet design. Just look at the Idz-30 or the F119 timetables for comparison (the F135 does not count because it is based off the F119). We have news that the WS-15 has already been flight tested, so incorporation into the J-20 should not take much longer. The point is that currently all major Chinese aircraft are using Chinese engines and that really says a lot of their progress in the gas turbines.You have still immature jet engine industries dear
You still have immature jet engine industries dear, first make a decent low bypass turbofan, WS-10 have a relatively high bypass turbofan and your WS-15 project started in early 2000 and its still not finished, Russian have no money but they have lots of experience in turbofan tech, they are developing turbofan since mid 70s , then you were only copying old Russian/Soviet tubojets in that era
Both countries are using interim engines for their 5th gen jets because one have no money to research, and you have lack of experience to design and build engines from scratchSo, China chose the mature AL-31 and D-30 at the beginning.
And now, what new mature engines does Russia have, by comparing with China?
F-119 have relatively short time-frame of development, started along with ATF program in 80s and it had been flying within in 10 years on with YF-23/YF-22 in late 80s, as far as i remember first flight of YF-23 with F-119 was in mid 90especially a clean sheet design. Just look at the Idz-30 or the F119 timetables for comparison
The WS-15 has already conducted flight testing aboard a modified J-11 (not the J-20). This was confirmed at the beginning of last year IIRC. Considering the WS-15 only completed high/altitude core testing in 2009/2010, the time table is not slow at all. Also, you have to take into account the numerous revisions the Chinese have taken to modify the WS-15 ... the current iteration is much more advanced than the one envisioned in 2006 due to incorporating new gas turbine technologies. This will also produce delays.F-119 have relatively short time-frame of development, started along with ATF program in 80s and it had been flying within in 10 years on with YF-23/YF-22 in late 80s, as far as i remember first flight of YF-23 with F-119 was in mid 90
The reason why the WS-10 was built on a CFM-56 core was because the MIC at the time (late 80s) did not have much funding and the limitations of China's military technologies. But a lot has changed since then ... the Chinese thrust to weight ratio 10 core demonstrator was tested successfully at the turn of the century (CJ-2000), which later became the basis for the WS-15. Experience is another thing that is very overrated ... it can be argued the Chinese had little experience compared to the US, Europe, or Russia in practically all areas of military hardware. Yet why have they been able to catch up and exceed in some aspects so quickly? The person playing catch up usually has a much easier and faster time than the person who is already at the lead.You have the money but lack experience but Russia have the experience your first engine from scratch will be ws-15 not WS-10 which is based upon CMF-56