Northrop Grumman B-21 Raider (LRS-B)

According to the metadata, the picture showing the B-21 outside was taken three days ago on 2022-11-29. But IMHO this picture could have also been photoshoped.
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Source: [MEDIA=twitter]1598928405734469634[/MEDIA]
View: https://twitter.com/ameliairheart/status/1598928405734469634?t=nqehsp9fbRyfHar3XKgTSQ&s=19

Unfortunately for us, but quite understandable for security reasons, the press wasn't allowed to use cameras with telezoom lenses and had to put away their smartphones into lockerboxes.
 
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Hansblix said:
At best what we are seeing is lessons learned or proven tech that was demonstrated in the 80s/90s through QUARTZ and AARS. I’m not saying this isnt a feat of engineering but this is a crowd pleaser we can fly in the public domain with tech that is more than likely not as advanced as projects from 30 years ago and best case 1:1 with them. Even 1:1 I’m very doubtful on.

NG won. It wasn’t the most advanced.
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I am baffled by your argument here, even the most cynical person is going to have a hard time getting on board with the idea of the USAF shelling out billions of dollars of taxpayers money unless it’s on the cutting edge in stealth technology for such an important mission.
 
I sleep true presentation :(

my thought on B-21: It a beauty

its more voluminous then B-2A, indicate more payload ?
That big landing gear suggest it

but there was something the Secretary of Defence say that surprised me

No need for near by deployment and NO Logistics for Operation
means the B-21 could fly it missions from US soil and no need for tanker ?

It will do Reconnaissance
So that Actually a RB-21 or more ?
The B-21 will support our forces across full spectrum of operations
The B21 is multifunctional ... Gathering Intel to Battle Management ... across our join force

Now that is not typical Bomber, that sound more like Multi-combat aircraft
What combine Bomber, Reconnaissance and flying commando post !
 
aonestudio said:

Northrop, U.S. Air Force Roll Out the B-21 Raider | Aviation Week Network

The B-21 Raider was displayed at the company’s secretive Plant 42 complex about 34 years after a similar ceremony for its predecessor the B-2.
aviationweek.com aviationweek.com
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The aerodynamics of this thing fascinate me; some comment is given in the article. The hundreds if not thousands of iterative computer designs have converged on several classic historical features that are generally ignored or forgotten by the mainstream.

The tailored airflow over the centre section echoes Reimar Horten's deep concern for the subtleties of the mitteneffekt (middle effect), which he never entirely resolved. He also wanted to improve the engine installation to a more conformal design.

Those intakes remind me somewhat of the NACA duct used for many small auxiliary intakes in the cold war era and trialled as an engine intake on the North American YF-93. No doubt the B-21 version is far more advanced, but the principle appears to be the same, and is I suspect the secret to decelerating the leading-edge flow at transonic speeds.

The wing outer sections have pronounced washout and, as far as I can tell, leading-edge droop. These features may be traced historically back through the majority of tailless swept wings, including the production Convair deltas, Avro Vulcan and Horten types, to the Dunne machines of the pioneer era and his 1909 patent. The first such design to fly, the D.5 biplane of 1910, received the first ever official certificate of performance for a stable aeroplane. Twenty or so years after that Ludwig Prandtl developed the theory of the bell-shaped lift distribution which offers the lightest structure and lowest drag for any given wing size, and for which these two features are necessary. Lippisch published a simplified calculation, which Horten adopted (though for some reason Lippisch seldom did). NASA only publicly caught up in this millennium, with Jonathan Bowers' PRANDTL-D flying wing project. Clearly, the key benefit for the digitally-controlled B-21 is not the inherent stability but Prandtl's minimal weight and drag. Once you sweep the wing, the stability comes with that package. Also of interest is that, right up to his rediscovery by Bowers, Prandtl was ignored by the mainstream and it was believed that these design features increased drag; this was voiced as a major criticism of the Dunne, and Northrop never incorporated them, not even in the B-2. Now, we see that they actually enhance the B-21's low drag characteristics.

The question I ask myself now is, did Northrop Grumman secretly take forward all these long-known but also long-obscure aerodynamic features, or did their computers arrive at something they knew nothing of beforehand? Either way, the B-21 looks like becoming a major vindication of all those maverick forebears.
 
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People design aeroplanes. Not computers. They are simply another analysis tool like wind tunnels, or glueing tufts on the outside. You use the tools to assess and provide evidence for decisions. You don't just press enter on the computer.

Features may look similar, but the rationale may be very different because it depends on the specific design goals and your geometrical constraints. e.g Dunne in 1910s wasn't trying to design a jet powered, transonic, stealthy aircraft
 
NCQ said:
sferrin said:
No way that thing could even carry one MOP let alone two.
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What from the reveal makes you think this thing couldn't carry even a single MOP? Based off the pictures we have it's only slightly smaller and if the rumors of it having two non-afterburning F135s are true it'll have about 85% of the thrust of the B-2. That all combines to it being able to carry at least one MOP.

Edit: Also, based off photos of the B-21 and B-2 reveals it seems the main landing gear for the B-21 is at about the same width as the B-2. Might mean two bomb bays (probably with two rotary launchers) like the B-2, or might mean nothing.
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Doesn't look like it would have the room to carry it internally.
 
SOC said:
sferrin said:
SOC said:
Screwed with one side, left the other alone. Blue points to apparent intake duct, red points to apparently solid bit. Interesting. It occurs to me that the intakes curving inward may suggest that the engines are a bit closer together - this may be of benefit in a two-engine aircraft if an engine goes out. I have now spent way too much time being amused by an overexposed image of an intake.

Also: "it might not carry as much/carry MOP/etc." Well what sort of warload do you need to whack targets in Syria anyway?
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Why would you need a B-21 to hit anything in Syria?
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Based on the last decade or two of experience, I'm being realistic about the kinds of conflicts we'd actually be willing to get involved in...
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I'd rather they built something that could handle worse case. If we go to war with China it will be a bit late to start building bombers then.
 
I decided to do some pixel counting on the photos.

I used the B-2 photo in front of that hangar posted by Maro Kyo (post#3164) to estimate that the hangar door is roughly 8.7m high. I am calculating the height instead of the width of the door, because it enables taking the measurement in the less distorted center part of the image. I used the man standing close to the door as a reference, since using the B-2 as a reference is not accurate, because it is so much closer to the camera so you would have size distortion from perspective relative to the hangar door.

Combining the estimated height with this relatively low distortion picture of the B-21, I am getting a ~40.9m wingspan for the Raider. The wingtips of the bomber are at roughly the same distance from the camera as the door hole of the hangar, which minimizes size discrepancies due to perspective. However, there is still clearly some fish eye type perspective distortion, since the bomber is a large object, and the photo is taken from relatively nearby with a short focal length camera. Using the same method on another picture I got ~41.7m, but I will refrain from posting it to keep the attachment sizes down since it doesn't add much.

If they keep this thing inside, we might have to wait a while for the definitive answer from satellite photos.
 

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Michel Van said:
its more voluminous then B-2A, indicate more payload ?
That big landing gear suggest it
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I think it looks chonkier because it's overall smaller. I think the bomb bay is the same as on B-2. I also think the peanut gallery decrying lost capability is also completely wrong.

In the 30 years from B-2 to this thing, we have gotten much better at making every single part of the aircraft and especially the structure. It's going to burn less fuel for the same thrust because the engines are more efficient, and require less thrust for the same speed because it's smaller and less draggy, so it needs to carry less fuel. It weighs a lot less because it's smaller, and also because composite structures have become dramatically lighter and stronger since the 80's. Remember, B-2 isn't even fully composite structure, because the state of the art back then didn't allow it. RAM coatings have seen multiple generations since the B-2 was designed, and while most of that was capability and durability, I'd take the bet that the modern stuff is also lighter.

I'm going to bet that it's smaller because it can be, as in, mission requirement was to match the payload and range of the B-2 and NG was able to do it with a much smaller package. We won't know if that's true for many years yet.

sferrin said:
Doesn't look like it would have the room to carry it internally.
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How are you arriving at that conclusion?

Note that the line of the fuselage on top is different from B-2 near the engines. Unlike with B-2, where the engine pods are separate from the central fuselage and there is a "valley" between them, on B-21 the central fuselage starts directly from the engines. This makes the payload bay proportionally substantially larger. Add to that the increased chonk on the bottom of the plane, and frankly, I'm going to bet that the total payload bay volume is not smaller than B-2.
 
sferrin said:
Doesn't look like it would have the room to carry it internally.
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As I said, the space between main landing gear looks basically the same to me so it should have the same amount of space for weapons bays as the B-2. But even assuming it only has space for half the payload, they're still going to design its one weapons bay to carry one MOP.
 
raptor82 said:
TIME ：
time.com

Exclusive: The Making of the Military's New Stealth Bomber

The U.S. is making a massive, strategic gamble that hasn't paid off in the past
time.com time.com
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This Time Article had a picture of a guy standing inside a composite duct with a cap on. I did some pixel measurements based on the assumption that the cap rim is 19cm wide (measured one that I have). This gives the duct a diameter of 43.5in, which corresponds very closely to the fan size of the F135.

So it looks like it is two engines.
 

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coanda said:
SOC said:
overscan (PaulMM) said:
Ramping up the brightness in the dark spots doesn't reveal a whole lot.View attachment 688241
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Is it me or does the outer portion of the inlet look solid?
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They look like blanking plates so you can't see the inlets.
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The upper inlet lips seem to vary in thickness though at the point of the inlet discontinuity, so I'd guess it's a permanent feature.

Additional thought: If they REALLY wanted to keep people guessing about the intakes, they could easily have done the rollout with red air intake cover plates in place...
 
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Very interesting jet for sure. Those inlets are incredible. So the theory of a 2/3rds B-2 appear to be correct. My semi-WAG is 215-230Klbs GTOW, empty weight in the 82-85Klbs with a max payload of 26-28Klbs. Internal fuel around 95-100Klbs. Maybe has a couple bays with the ability to use two rotary launchers of six 2klb munitions each for a max of 12. Just gotta buy a lot of these
 
BDF said:
Very interesting jet for sure. Those inlets are incredible. So the theory of a 2/3rds B-2 appear to be correct. My semi-WAG is 215-230Klbs GTOW, empty weight in the 82-85Klbs with a max payload of 26-28Klbs. Internal fuel around 95-100Klbs. Maybe has a couple bays with the ability to use two rotary launchers of six 2klb munitions each for a max of 12. Just gotta buy a lot of these
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I hope those bays are bigger than that.
 
steelpillow said:
aonestudio said:

Northrop, U.S. Air Force Roll Out the B-21 Raider | Aviation Week Network

The B-21 Raider was displayed at the company’s secretive Plant 42 complex about 34 years after a similar ceremony for its predecessor the B-2.
aviationweek.com aviationweek.com
Click to expand...
The question I ask myself now is, did Northrop Grumman secretly take forward all these long-known but also long-obscure aerodynamic features, or did their computers arrive at something they knew nothing of beforehand? Either way, the B-21 looks like becoming a major vindication of all those maverick forebears.
Click to expand...

That is quite the question. It'll keep me up at night for a bit :) How many decades before we can get an interview on the basic aerodynamics - three, four?
 
pedrospe said:
Just making a rude comparison between the B-2 and the B-21.
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Well, looking at the two workers(?) in the background, compare them against the people who were walking with the B-21 when they rolled it out. Unless they're drastically different heights, I'd say the B-21 is smaller than this comparison makes it seem.
 
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zaphd said:
I decided to do some pixel counting on the photos.

I used the B-2 photo in front of that hangar posted by Maro Kyo (post#3164) to estimate that the hangar door is roughly 8.7m high.
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I doubt hangars are the same looking at taxiway markings.
 

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