a reply to: Zaphod58
Then, if the B-3 image is to be at least somewhat believed, I can see the designs breaking down like this:
LockBo: Leveraging Lockheed's quiet boom technology that may or may not actually be proven, and leveraging Boeing's experience designing the Sonic
Cruiser, I can see those two design families merging together into a platform capable of Mach .9-1.3 cruising while producing a negligible sonic boom.
In essence, the same flight profile as the Aerion (over the US) and a couple of the other SSBJ proposals. Combine those design goals with the
realities of the chines, etc needed for stealth, and you can tell where the upper design on the "building the B-3" image may have come from, as it
looks like the Sonic Cruiser, an SSBJ, and the Tacit Blue thrown in a blender. Given it's design as a transonic-native craft, I'd imagine that some
compromises needed to be made to save weight, etc, and I'm guessing that while it's ADVENTs would have been powerful enough for it to supercruise,
that IR performance might have suffered and the fluidic vectoring system that's commonly seen paired with the ADVENT in diagrams would also be
withheld, with the craft instead relying entirely on its control surfaces.
Basically, in terms of performance, look at it as an Avro Vulcan for the 21st century.
NorGrum: Building on the B-2 and the X-47B, Northrop's design would be a familiar cranked-kite shape, using extensively buried ADVENTS for
propulsion. It is not a transonic native design, instead having a cruising flight envelope nearly identical to the B-2. It does, however have much
more in the way of IR suppression thanks to its buried engines, and its fluidic thrust vectoring combined with advanced boundary layer control systems
allows it to fly "clean" like the B-2 and control itself without needing to deflect its control surfaces much, if at all, which gives it a lower RCS
than the LockBo design. In terms of speed, its cranked kite design, with the winglets set farther back on a much more elongated diamond-shaped
fuselage than on the shorter, wider, carrier landing-optimized X-47B, allows it to hit speeds of Mach .9-1.2 in a dash, with the advanced control
systems allowing it the yaw, etc control to hit such speeds safely. However, at those speeds it will create louder booms and it's not able to
maintain such speeds for nearly as long as the much more optimized LockBo design would.
Basically, in terms of performance, if the LockBo design was the Vulcan, the NorGrum design would be more like the Handley-Page Victor.
Industrial base concerns aside, the sticking points for the LockBo design would be the weight management and composite airframe required to hit the
needed efficiency levels so that it could sonic cruise effectively while carrying an adequate payload, as it would be a much more aerodynamically
ambitious design. Meanwhile, the sticking points for the NorGrum design would likely be controllability and integrating its various different
advanced aerodynamic control systems, with weight/performance being slightly less critical than on the LockBo bird.
edit on 19-1-2016 by
Barnalby because: (no reason given)