This sound interesting, do you have any source for this?
Shenyang FC-31 / J-31 Fighter Demonstrator
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This sound interesting, do you have any source for this?
This is the truth -- THE FOUNDATIONAL TRUTH.
Regarding radar cross section (RCS) the simplest and most effective finite shape/body is the sphere. It has only two modes of radiation: specular and surface waves. Other than the sphere, the goal is to minimize the quantity of modes of radiation in any complex and finite body. The plate, cylinder, cube, pyramid and other simple shapes has specular, surface waves, and edge diffraction modes. After the sphere is the ogive or 'flying saucer' shape.
The reason why we are instructed with infinite area and perfectly conducting surface is because we should be focusing on a particular mode as part of the learning process. But in the real world, we have to negotiate finite bodies and attempt to control when possible and eliminate if possible any radiation mode.
So when it comes to major structures on a complex body like an aircraft, the YF-23 has four major flight control structures: the two wings and the two ruddervators. The F-22 have six: the two wings, two vertical stabs, and two horizontal stabs. The vertical and horizontal stabs forms two corner reflectors which while are not 90 deg corner reflectors, this complex compound structure should be avoided whenever possible. So for a complex finite body like an aircraft, there are specular, surface waves, edge diffraction, corner reflectors, tunnels, and concave amplifiers (cockpit). All are modes of or radiation generators.
The J-20 also have six major flight control structures that are also radiation generators. I know many people do not believe the J-20's canards to be significant RCS contributors but they are wrong based upon this truth. If access door to fuselage surface gaps are worthy of the 'saw tooth' treatment to redirect edge diffraction signals away from source direction, how is it that the flippity-floppity canards are not significant contributors?
If we look at the F-117, we could lose count on how many surface radiation generators there are thanks to the angled faceting technique that gave us so many surface discontinuities -- where the plates joined or edge diffractions. Yes, those joints were precisely calculated to minimize returns to source directions. But if there is/are technique(s) to minimize the quantity of structural radiators, why not use them? Curvatures. Because the aircraft is a finite body and because current absorber technology have yet to be %100 effective, why not keep the radar signal on the body for as long and as much as possible? Curvatures.
How much lower RCS thanks to less radiation generators, or lesser quantity of RCS contributors, does the YF-23 have -- statistically speaking -- than the F-22, we will not know for a very long time. Perhaps it was much lower but the USAF deemed the YF-23's low RCS versus the current radar systems (of friends and foes) to be overkill and decided to have the F-22's superior maneuverability as well. Perhaps the YF-23's lower RCS was not tactically sufficient and the USAF deemed the F-22's superior maneuverability to be a worthwhile trade for the F-22's slightly higher RCS. Perhaps someday soon Northrop will be able to tell us how much lower is the YF-23's RCS compared to the F-22's but my sources at Nellis and Hill opined that the USAF should have gone with Northrop.
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Montgomery asked if China was angry at the British, Mao said no, not any more. Henceforth, they were friends, and exchanged gifts. Not sure what China gave (I presume leaving HK free from revolution and in British hands for the time being), but the Brits gave the jet engine, and support for China in becoming a member of the UN security council.
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I think many people make that claim in the comparative sense, in that canards are no worse than horizontal tail planes.
As standalone structures? No worse or even lower in measurement. But that is not how total RCS is calculated: Sums the discrete measured figures.
The interaction between discrete structures is what made the corner reflector undesirable in RCS control. This make location, location, and location, just like real estate sales, crucial for RCS control. Corner reflectors are fixed and this make them predictable in terms of level of contributorship. Moving structures are less predictable. Put both fixed and moving structures on a moving complex body and we have internal weapons bays, absorber on leading edges, and other methods in trying to minimize returns to source direction. That is why we have to measure the entire aircraft despite the fact that we have binders full of discrete standalone measurements of individual structures, large and small.
We knew that with the F-117 with its many edge diffraction generators, as the aircraft passes through a beam, we have target scintillations. Not enough to attract the attention of 'pre-stealth' radar systems, but now that 'stealth' and how the principles works are known, we have to move away from that design.
For example...
Note what the comment said about maneuver restrictions in combat. Even as minimalist a design like the flying wing B-2, target scintillations because of low level radiation generators, like the split wing tip rudders to create asymmetric drag for turning, are sufficient to discourage its usage.
sdleio
Junior Member
Currently use 2x RD-93 aircraft engines,also used by JF-17 fighter
new pic
Why the nose is also painted the same way as J-20 2002 with speculate avionics fitted. Does this means J-31 1031 is also fitted with avionics? Maybe Shenyang want to fasten this project and complete the same time as J-20 to attract PLAAF and PLAN order more of them?
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