Measuring at 0.6 mach is useless and pointless
I think it’s to provide basic intake pressure, and both ot the curve matches this, AL-31F gets it’s 12200N at about 0.6 mach too. 0 speed is not a normal working condition for engine, I think it’s the reason.
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The latest WS-10A does not surge anymore, as material science improved. The limiter is removed now.
It is true that WS-10A had many issues in the beginning.
Good to know
It is unusual for comparison as the intake and design of an engine will vary greatly at 0.6 mach. The bench uninstalled thrusts can be used for further calculations - the thrust specifically at 0.6 mach lacking context regarding the intake are not so easy to use.
For comparison engine to engine the performance on a bench is most reliable when you are sharing the data for something that may be used in a variety of airframes - which applies to the WS-10.
I think it’s a widely accepted standard, when testing bench thrusts, engine is given some intake presure to make sure the engine runs smoothly. Though I didn’t find some files about the standard yet
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measure at mach 0.6 or 0.3 or even 1.2 if give them show that the engine has better performance at a certain speed range we take give them we do not throw it away
We can say that the difference is in the margin of error.And if you turn on a special OP mode for the AL-31F, then there will be no difference at all.
The Chinese model incorporates FADEC and is far newer - the equivalent in Russia actually also has FADEC now and potentially longer lifetime at the same thrust ratings as compared to the WS-10 counterpart. China wants to catch up and is making good effort but they are not there yet. They still do not even have a variable bypass design in testing or production to my knowledge.
The AL-31F has never had a FADEC
It’s difficult to gauge Chinese engine development in general, it’s only around a couple of years ago that technical bottlenecks regarding WS-15/WS-19 had been completely solved and they are ready to enter mass production.
A lot of the things happen behind closed doors unfortunately. There very well could be variable cycle design in testing but due to usual PLAAF opsec, it’s hidden as it is in early stage of development. There are definitely papers authored by Chinese scientists in the aviation field regarding variable cycle technology, so I think they are aware of the advantages it would bring.
But considering that pre-2010, WS-10A was pretty much in an state so bad that it couldn’t be utilized on J-11B initially, China has come pretty far.
I didn’t say anything about the AL-31, I am just comparing the generational gap in engine design that Russia has over China.
So what is difficult to gauge? We know where they are at and their progress has been rapid.
Not too many public statements, reliable published statistics compared to other nations, although this is a thing with regarding the Chinese military in general.
Some sources say the test of the prototype already started years ago, it’s said to be a tri-bypass engine similar to XA-100, recently they exhibited the engine’s frame, which is clearly a variable bypass design.
WS-10’s core design is closer to F110, which has big difference to AL-31F, it will be strange to have same curve as AL-31F. Besides, the thrust difference becomes bigger in higher altitude/speed.
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That claim is unsupported, and the thrust curve being similar to the AL-31 contradicts it greatly as you indicate.
This doesn’t show a variable bypass, only a three stream flow. This could be used for an augmented turbofan with external ramjet or simply reduced IR signature by utilizing larger amounts of free-stream air. The claims that they have already tested a prototype are inconsistent with current trends focusing on non-variable bypass technology.
They are far behind on the materials sciences required to utilize even standard F119 style static bypass augmented turbofans to the same degree the US has since the early 90s and late 80s. If they wish to skip variable bypass altogether and go straight to variable cycle designs they will need to make some pretty big strides.
It’s basically classified, only some rumors from “related person”, and some paper or other indirect sources. But yes, there isn’t direct source about it’s tested.
though this is tested and reported years ago.
This is a picture of the J-15 production line, which clearly shows that the J-15 uses a lot of composite materials. Does this mean that the J-15 will be lighter than the Su-33, and much lighter?
The top coat is made of composite but most of the underlying frame is hidden in these photos. You can see metal being used around the engines, spine, etc in the same spots as the Su-33. I don’t foresee massive weight savings based on that picture alone.
I mean we can sort of just do J11A-J11B weight saving and apply it to Su33-J15, do take it with a pinch of salt, the area of composite material use are nearly identical and both transferred from N001 to 1493, should be (in theory) same avionics as well.
To be honest, even the J-11B only lost 700-800 kg in weight. Considering that next year the J-15 is likely to appear, I would be satisfied that even the J-15 can only be reduced by a few hundred kilograms.
All I am saying are that more images are needed than what was provided to show extensive use of composites. Surely some weight savings were made but it is lost in other areas. If you want Gaijin to accept something you will likely need actual documentation of some sort.