Northrop Grumman B-21 Raider (LRS-B)

Also the timing is really weird too… Why test aerial refueling now…? The B-2 test fleet cleared that in the first few months of flight testing.
 
Last edited by a moderator:
Anyone have any idea what those brown spots on the right side, visible in that side refueling shot, in that dark area could be?
 
Last edited:
those darker trailing edge features sure are good for a fun time.

Is it a far-out secret government tech that greatly reduces contrail formation?

Is it a far-out secret alien tech that greatly enhances contrail formation?


Is it just be a good place to put two linear, wideband, multifunction aesa arrays arranged to well-cover the rear quadrants?
 
JoshuaH said:
It’s really weird… At first flight of the exact same aircraft, the exhaust region was either black or a very dark color.
Click to expand...
Maybe there's a combination of heat-tolerant RAM, very efficient bypass mixing to get the plume as cool as possible, and airflow control over the surface to keep the exhaust gases separated and stood-off (even by a pretty minor distance) sufficient to keep surface temps reasonable. Definitely easiest to do on a platform that doesn't operate at high AoAs. Could bleed a little bit of bypass into a French drain type outlet combined with careful surface shaping.

Similar principle to the porous boundary cooling in turbine blades.
 
Sferrin said:
And something is still required on the bottom.

View attachment 809147
Click to expand...
They just have to cool the aft deck. The B-2 used the aft deck tiles, I'm sure the B-21 may be using a ceramic coating. As an example, the production F-23 was not going to use the Lamaloy actively cooled tiles for the exhausts, it was going to use passively cooled, advanced ceramic tiles instead, just an evolutionary step. Northrop/NG has been working and evolving this tech for a long time. Looks like the 21's exhaust openings are farther forward as well as compared to the B-2, that large aft deck area is probably very good at thermal dissipation. Northrop/NG VLO platforms share a lot of design commonalities, use, improve and evolve what works.
 
Hydroman said:
It was going to use passively cooled, advanced ceramic tiles instead, just an evolutionary step.
Click to expand...
"Three passively-cooled alternate trough materials have proved promising in ground tests. “We’ve had some breakthroughs,” Rooney said. “We'll pick the lightest and cheapest for full-scale development.” One material is flexible blankets. They have been tested at full afterburner and are expected to last 1,000 hrs. Another alternate is ceramic tiles, and a third is ceramic matrix materials. Rooney believes ceramic matrix has the best prospects for light weight."
 
JoshuaH said:
Also... What might be the purpose of the row of panels in front of the forward spar...? Since it probably does not have any leading edge control devices, what could be occupying that space...?
Click to expand...
I would guess access so if they ever need to modify/remove/repair the leading edge, or components inside it.
 
They may be using the bypass air from the fan as a sheet of cooler air between the main nozzle and the upper surface and the hot core flow to help keep the upper surface somewhat cool, as opposed to completely "wrapping" the bypass air around the core flow. Also, it looks like the rear nozzles may actually be slightly higher than the rear deck of the wing, as far forward as they are, raising them up a bit from the rear surface. I also noticed the upper surface of the nozzle on the B-21 is a pointed facet, as opposed to the V-cut on the B-2 to maybe also help mixing the core and bypass flows to cool it faster? Those are just some guesses as to what they may be doing at the exhaust.
 
Sferrin said:
Radars would be on the bottom side. Maybe they're access from the top though. Wonder if the B-2 has similar panels.

Nope. Nice and clean.
Click to expand...
Yeah that is one of the reasons I am curious about these panels: the B-2 does not have them… The bank of apertures are on the underside, a bit far away from these places…
 
Sferrin said:
And how do you do that without access?
Click to expand...
Probably just find the screw holes buried under the RAM… If the leading edge (primary bulk absorber, RAS) is going to be removed, the surface wave absorber (the RAM paint on the surface) is probably going to be repainted anyway…
 

Similar threads

Back
Top Bottom