J-20 5th Generation Fighter VII
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Those weapons bays on the SU-57 aren’t connected. How would you go about fitting the kinzhal in there?
Hi
what about the possibility of reducing the number of missiles
in internal bay & then fit in couple of PL17/21 is there any possibility
& what are the chances of firing Vlong range from outer bays will
the stealth will be able to work on j20 after firing these long ranges
from outer pylons
thank you
what about the possibility of reducing the number of missiles
in internal bay & then fit in couple of PL17/21 is there any possibility
& what are the chances of firing Vlong range from outer bays will
the stealth will be able to work on j20 after firing these long ranges
from outer pylons
thank you
I think the best bet is to develop a ramjet missile with a throttleable motor or a two stage rocket motor to increase range
Your questions boils down to only one "Did J-20 choose delta canard deliberately?". The answer is yes. According to the chief designer.
It seems to me that your proposed reason for the canard and its size is control. That is partially true, there is another reason "lift generation by vortex from canard". The latter reason is even more prominent in the designer's mind.
J-20 is more maneuverable not primarily due to larger canard size, but due to the more lift generated by the combo of canard and leading-edge.
The size certainly plays a role, but it is only part of the whole equation.
No possibility, it's simply far too long.
But you can develop a new, shorter, and stubbier missile.
If you can develop a fully detachable pylon&ensure it separates smoothly - yes, you can.
But on average - it makes more sense to carry them on flankers, which are better oversized payload carriers in the first place - and oversized/very long range missile employment doesn't really gain all that much from stealth carrier(in some ways - the opposite is true).
Delta-canard design increases stall AoA (angle of attack) thus an aircraft of delta-canard configuration usually has good high-AoA control, instantaneous turn, and climb. At the same lift, delta wings tend to be lighter and accommodate more internal space.
Their disadvantages are, under Mach 1, they produce more drag compared to more conventional swept wings. At the same wing area, they usually generate less lift except at really high-AoA. Also, the drag in extra angles enabled by delta wings tends to be horrible.
To summarize
Climb and acceleration -> Delta
Top speed -> Delta
Internal space -> Delta
Instantaneous turn -> Delta
Supersonic cruise lift/drag ratio -> Delta
High-AoA control -> Delta
Max altitude -> Swept
Subsonic cruise lift/drag ratio -> Swept
Sustained turn -> Swept
Canards are a different matter. The rule of thumb is in stable aircraft like old fighters and all non-fighter aircraft, the wing surface at the rear needs to have a lower coefficient of lift. So in stable aircraft canards mean suboptimal main wings. This is made worse by the fact that canards are a control surface and thus need to stall the last. This almost always means less camber or more swept on canards which in turn means you will have to decrease your main wings' coefficient of lift even more (remember they have to have it lower since they are at the rear). Canards like all surfaces also generate both downwash and upwash at different positions which means even more suboptimal design choices are forced on the main wings.
All these problems go away when you enter the world of modern fighters. Fighters, especially delta-wing ones tend to have extra surfaces on their main wings which means the canard can stall earlier without problems and the lack of a requirement of stability means the main wings can still have a higher coefficient of lift. Canards still increase the drag but they also add extra control authority and delay stall even further.
lcloo
Captain
Thanks for the excellent information. Is it possible if you can further comment on the surface area marked "A" and "B" of the below photo?
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Fighters had been using their bodies for extra lift for 50 years. It significantly increases available lift without much weight penalty. So tubular fuselages disappeared. Internal weapons bays also impose fuselage internal volume demands.
Taper on the A? I don't know. You would need design papers and expertise to pinpoint the reason, which I have neither. Aerodynamics, internal volume, airframe strength, weight, radar return all need to be optimized according to requirements and they sometimes compete with each other. The choice should have been a compromise they reached after many experiments. But as far as I see it hides canard roots from sensors towards the front. It also increases the surface incidence angle (regarding the surface normal) for all sensors located towards the frontal hemisphere. So I can guess that it is beneficial for stealth. We also know the J-20 has S-ducts so a taper might also be a structurally natural choice.
Twitter post from a credible source predicting annual J-20 production for FY2023 to be >100 airframes
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