The canted fins acted as shield on engine heat signature on both sides of the aircraft.
Not likely. Not if the exhausts are already recessed the way the drawings have them.
I doubt the fins return significant radar signature since J20 and F-22 have them. And F-22's canted tail fins are huge relative to the airframe.
The J-20 and F-22 are fighters, so at the current state of flight controls technology, fighters needs all three axes stability and maneuverability surfaces.
There are three rules in designing a low radar observable body:
- Control of quantity of radiators
- Control of array of radiators
- Control of modes of radiation
What is 'significant radar signature' is relative to the overall body. Under Rule 2, the size of each flight controls element is precisely calculated to radiate (reflect) as minimally as possible while taking into consideration the need of aerodynamic exploitation for stability and maneuver, in other words, even one mm is important. Radar asks if the surface area can be reduced by one mm, Aerodynamics says the area needs to increase by two mm. And both sides comes to a compromise.
So you have no basis for your doubts.
As far as the American B-2 goes. The bomber does not need to be as maneuverable as a fighter, so the vertical stabs are eliminated. The flying wing design have inherent difficulty in controlability in the yaw axis, but the B-2's FBW system is proven to handle that issue. So yes, under the three rules, it is possible that the Chinese 'stealth' bomber design do not have as sophisticated a FBW system as the American bomber, unless the Chinese bomber is planned to be maneuverable similar to a fighter.
danke!
