Last time I was in a dinner with guys including Yankee（养鸡） talking about turning performance of J-20, I got the information that the sustained turn performance at subsonic speeds is pretty comparable to that of a F-16. On what altitude/detailed speed settings he did not say. But to me it totally make sense when J-20 is using AL-31F thrust level engines.
And speaking of vertical climb, the Russian Knights at Aero India 2013 performed a vertical climb that sustained longer than that of J-20 at Zhuhai airshow 2016, without any visible shock diamond. So it's reasonable for J-20 to do the same.
1.) The first 15 seconds was a loop, not a vertical climb. The second climb is a high angle, near vertical climb that made Flankers family famous. I estimate the angle, during the climb, to be around 65-70 degrees.
2.) I see no long bluish flame shooting out, either. Probably using military power.
3.) The Su-30SM used by the Russian Knights weights empty at 17,800kg and uses the AL-31FP engine with Max Thrust 125KN. (I estimate the J-20, is at least two tons ,more than F-22's 19.7 tons. There is more than 4 tons difference of weight between Su-30sm and J-20. Also how much fuel they are carrying is also an important factor. So its important to see
when did they demonstrated a real vertical climb, at the beginning of a long demo or at the end.)
4.) So I see no reason to believe that Su-30SM can't do, what we have seen in this video. It has excellent aerodynamic characteristics that allow it, to climb with such high angle, without losing control.
5.) But at 70 degrees, is at the edge of the
wing stall limit, of all modern fighters, including the Su-30, F-22, T-50 and J-20.
Beyond that, the wings lose its ability to create upward lift, and must rely solely on the engine performance to provide the vertical lift, necessary for the genuine vertical climb, in a sustained manner (that is, not a loop).
Further more, the high attack angle, makes the whole plane acts like a giant air brake, that quickly bleeds the horizontal speed to zero. So it does not make sense to point your nose that high, if you want to climb fast.
A slow vertical climb is usually done to demonstrate that you have abundant excess engine power.
Issue is only that this "Some guy" is pupu; I'm sure Yu know him. I don't follow rumors.
I got my informations from reading technical articles and make up my mind, if the performances of J-20 fits what I have read.
So IMO even if I agree to be careful and not to take any Big Shrimp's word for gospel, he is surely not only an ordinary "some guy".
At least You have to admit IF these reports that a WS-10-version WILL power (and so never did so far) the chances of the two other options became dramatically smaller. Or not?
I actually don't know him. Never read anything he said. Some one might have mentioned his name in the past, several months ago.
WS-10's design was Frozen in 2006, and went into serial production around 2009.
And J-20's appeared in late 2010. If a new engine, other than the original Ws-10
, powered J-20's first flight, then this engine must be developed and bench tested between 2006-2010.
And this engine has 3-D TVC, 210kN thrust as we have seen.
There are still no words that another version of WS-10 is being developed. No pictures, no official announcements. Nothing. I believe the WS-10 line, will be dropped, in favor of Ws-15. That is, no more variants, after the first Ws-10.
But there are plenty of rumors, and even official acknowledgment that there is an engine called WS-15, that is its intended engine for J-20. In 2007, an insider even wrote a long article described how this engine's core was developed, and that it passed all ground bench tests in 2005, and in 2006, officially established the project to complete a TWR 10 engine.
By the way, WS-10-version, is not AL-31, isn't it?
Did you dropped your AL-31 theory, in favor of the WS-10-version theory?
