Chinese Engine Development

GiantPanda

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Take this for what you will, but CJ-1000A apparently has finished full environmental testing and have now accumulated 6142 hours of this testing in highland icing and bird strike and other scenarios. It is estimated to get CAAC type certificate in Q2 of this year and first will be installed in Q3.

I'm not sure who originally published this story. Could be made up.

Seems too good to be true -- for any other country.

But China is, well, China. Worth keeping an eye out.
 

Blitzo

General
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Take with a mountain of salt right now but I’ve read some reasonably reliable rumors that VCE progress is ahead of the schedule. Can’t wait till TWZ catches wind of this a couple of years down the road :).

Specifically it boils down to whether J-36 will even use WS-15 as an interim when it LRIPs.

I suspect the engine identity for J-36 and J-XDS will be complicated for a while due to lack of ability to correlate engine type with nozzles/exhausts -- they may be completely independent by this point.

Most of the foreign defense media aren't even aware of PLA VCE efforts in the aeroengine domain, so I wouldn't put particular interest in what they report in the future no matter what happens.

I also think we should avoid bringing in the opinions of other outlets and authors or communities for the sake of mocking them.
That sort of schadenfreude has a way of backfiring and is less disciplined than we would like to be.
 

siegecrossbow

Field Marshall
Staff member
Super Moderator
I suspect the engine identity for J-36 and J-XDS will be complicated for a while due to lack of ability to correlate engine type with nozzles/exhausts -- they may be completely independent by this point.

Most of the foreign defense media aren't even aware of PLA VCE efforts in the aeroengine domain, so I wouldn't put particular interest in what they report in the future no matter what happens.

I also think we should avoid bringing in the opinions of other outlets and authors or communities for the sake of mocking them.
That sort of schadenfreude has a way of backfiring and is less disciplined than we would like to be.

The sound it makes will be very different, bigger than that of AL-31 and WS-10C or even WS-10C and WS-15 for the J-20. It will be a you’ll know when you hear it type of deal.
 

taxiya

Brigadier
Registered Member
From this side it is claimed that the CJ1000 is 7% more efficient (in what regime) than the Leap-1C. How much less efficient was the 1C to the 1A/B?
According to wikipedia 1B is 4% less efficient than 1C and 1A. 1C and 1A are equal in fuel efficiency at 14.4 g/kN/s, 1B is 15. The source of these figures are from Russian article regarding development of PD-14 as to compare to LEAP.

Since all Leap-1 variants are based on the same technology, the difference is only because of compromise made for factors outside of the engine. With my limited knowledge I would guess that 1B being less efficient (Thrust Specific Fuel efficiency) is likely due to its 5 LP instead of 7 LP in A and C and smaller BPR. Less LP means less power generated from the hot gas of the same core, therefor less power to drive the fan leading to less mass of air to pull while burning same amount of fuel. There is really no difference between A and C except slightly lower BPR of 1C, but since the driving power from LP are the same, 1C's fan can run slightly higher RPM to pull equal amount of air in unit time while burning same amount of fuel.

In conclusion, although there is difference in numbers I would not use the phrass "more or less efficient" regarding LEAP variants.
 
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latenlazy

Brigadier
According to wikipedia 1B is 4% less efficient than 1C and 1A. 1C and 1A are equal in fuel efficiency at 14.4 g/kN/s, 1B is 15. The source of these figures are from Russian article regarding development of PD-14 as to compare to LEAP.

Since all Leap-1 variants are based on the same technology, the difference is only because of compromise made for factors outside of the engine. With my limited knowledge I would guess that 1B being less efficient is likely due to its 5 LP instead of 7 LP in A and C and smaller BPR. Less LP means less power generated from the hot gas of the same core, therefor less power to drive the fan leading to less mass of air to pull while burning same amount of fuel. There is really no difference between A and C except slightly lower BPR of 1C, but since the driving power from LP are the same, 1C's fan can run slightly higher RPM to pull equal amount of air in unit time while burning same amount of fuel.

In conclusion, although there is difference in numbers I would not use the phrass "more or less efficient" regarding LEAP variants.
1B also has a smaller fan. Just remember the Leap 1B is the version they had to adapt for the 737MAX.
 

ACuriousPLAFan

Brigadier
Registered Member
Take with a mountain of salt right now but I’ve read some reasonably reliable rumors that VCE progress is ahead of the schedule. Can’t wait till TWZ catches wind of this a couple of years down the road :).

Specifically it boils down to whether J-36 will even use WS-15 as an interim when it LRIPs.

If I recall correctly, sometime ago, one of the big shrimps (either on Weibo or Twitter) retorted against a comment to a post that the US is ahead in ACE/VCE development for the 6th-gens with the "The US hasn't even started high-altitude engine test bench trials with the VCE/ACE meant for the F-47" reply (or something of similar effect).

And recall that we've seen those VCE/ACE slides by CAS from November last year (where high-altitude test bench trials have already been completed, and their VCE/ACE isn't even meant for the J-36 and J-XDS/50) - I think China's VCE/ACE development progress certainly is getting somewhere encouraging (if not at the same pace as the VCE/ACE from CAS at least).
 
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