J-10 Thread IV
- Thread starter Jeff Head
- Start date
P&W PYBBN, GE AVEN (MATV), Salyut's nozzle, KliVT... they're all minor variations on the same basic principle, in the same way that GE's and P&W's non-TVC nozzles aren't fundamentally different. Given the two-part outer petals, the closest counterpart to this new Chinese nozzle is Salyut's design. It may be a result of using a short divergent nozzle section similar to the PW1120 (Lavi engine) for lower weight while accepting a certain thrust penalty:
Doesn't explain why Salyut does it though, their divergent section seems to be of regular length.
As for Eurojet's TVN, that design was a simplified variant of the PYBBN/AVEN etc. concept which removed the requirement for separate throat & exit area unison rings by splitting the single remaining ring into upper and lower halves joined by a hinge. These could 'wink' like eyelids to control exit area, with the drawback that exit cross section did not always remain perfectly circular (small thrust penalty).
As I recall an article about the J-10’s TVC nozzle that came out when it first showed up said that the nozzle design was supposed to both save on weight and minimize thrust penalty.
It's always a compromise between weight, thrust penalty and complexity/cost. If minimizing thrust losses is the paramount concern, Saturn's ball joint solution is probably the gold standard: all cross sections always remain circular, long divergent section, independent exit area control (although the latter is a feature of all the TVC nozzles discussed here). Requires loads of actuators though.
A version of Eurojet's design with a WS-10/PW1120-style short divergent section would sit at the opposite end of the spectrum (weight/complexity optimal, higher thrust penalty).
A version of Eurojet's design with a WS-10/PW1120-style short divergent section would sit at the opposite end of the spectrum (weight/complexity optimal, higher thrust penalty).
The USSR had virtually no non-military RF industry and zero access to COTS electronics, yet kept pace pretty well. It's an unreliable indicator.
I’m not using that point to argue for why we should expect Russia’s military RF capabilities to be behind China, but why we shouldn’t expect China’s to be behind Russia’s. Totally different uses of the point.
Or the divergent section is no shorter than it should be. But the reason of two section outer petal is simply because of the different location of the bar attachment, see the red circle.
