J-10 Thread IV
- Thread starter Jeff Head
- Start date
”只待几番寒彻骨” sort of hints that this thing is still years away to be combat ready.
Pretty good poem artistically.
Pretty good poem artistically.
Good catch. I've edited my translation accordingly.
To be honest, the differences between AVEN, PYBBN and the Salyut/Klimov nozzle seem to be mainly in the actuator arrangement and numbers - the basic principle is otherwise virtually the same.
AVEN and PYBBN are both based on having two sets of actuators mounted on the rear of the engine casing which each act on a separate concentric sync ring, one of which is linked to the convergent petals, the other to the divergent petals. By translating these rings fore and aft independently, nozzle throat and exit area can be expanded or contracted separately (on earlier, non-vectoring con/di nozzles the throat/exit area ratio varies according to a fixed relationship defined by kinematic linkages - e.g. F100, F110, F404/414 & AL-31F). For controlling the thrust vector, both deflect the divergent petals asymmetrically by tilting the associated sync ring (the result of simply extending the actuators on one side further than on the opposite one).
Salyut pretty much makes only two modifications to this principle, at least one of which the Chinese nozzle seems to have adopted: firstly they carry over the convergent section actuation from the AL-31F, which mounts the actuators on the moving flaps rather than the fixed engine casing and uses the rear flange of the casing as a (stationary) sync ring. Secondly (and this is the deviation from its US counterparts which the Chinese appear to have adopted) the external turkey feathers are split by an articulated joint half way along their length, so the part shrouding the convergent section doesn't tilt with the thrust vector while divergent section fairing does.
Even the ITP/Eurojet thrust vectoring nozzle is little more than a clever variation on this concept which gets away with fewer actuators and only a single sync ring by splitting the ring into hinged "eye lid" halves for exit area control (exit cross section deviates markedly from circular when contracted by closing the eye lid though).
Long story short, it's hard to judge why the Chinese adopted something closer to Salyut's solution as the differences between the various concepts are so slight to begin with - I doubt one is significantly lighter than the other (possibly the ITP nozzle does a bit better than the rest at a small thrust penalty).
BTW, there is one (non-vectoring) con/di nozzle design that I'm aware of which had independent throat & exit area control all along... the RD-33! It also has an actuator arrangement which is very unlike any other and pure genius really - there are two groups of actuators (one each for the convergent and divergent sections) linked end-to-end into rings encircling the nozzle. By extending or retracting the actuators the circumference of each ring can be expanded or contracted to independently increase or decrease the throat and exit areas. Very elegant and neat!
So, a radar blocker - makes sense. Thanks!
drunkmunky
Junior Member
For the TVC conversation, can someone explain to me what that piece in the middle of the outlet is? The one drawn in the patent section?
Thanks,
Thanks,
Since the cockpit is not visible, how can you tell that it isn't a J-10S?
It might be. Now that I take a closer look at it, the cockpit does seem to be a bit more bubbly than the J-10A's. Nonetheless, I thought the J-10S' third batch was finished years ago so this should be an older picture, yes?
