vs.Mess up agile, and you simply do not get the return on investments you would like. We are straying off-topic.
FUBAR if you get it wrong.
B-2 | B-21 | ||
We (lbs): | 158000 | 61817 | |
Wg (lbs): | 376000 | 148155 | |
Wf(lbs): | 167000 | 65338 | |
Wcrew (lbs): | 1000 | 1000 | |
Wpayload (lbs): | 50000 | 20000 | |
Engine Thrust (lbs/each): | 17000 | 13397 | |
No. of Engines: | 4 | 2 | |
Wingspan, b (ft.): | 172 | 108 | |
Wing Area, S (sq. ft.) | 5140 | 2011 | |
Wetted Area Ratio: | 2.4 | 2.4 | |
Wetted Aspect Ratio: | 2.4 | 2.4 | |
L/D (max): | 22 | 22 | |
Wing Area Scale Factor: | 0.39 | ||
(used to scale fuel load) | |||
Total Thrust (lbs): | 68000 | 26794 | |
T/W Ratio (Take-off): | 0.18 | 0.18 | |
Wing Loading (Take-off): | 73.15 | 73.67 | |
Fuel Fraction: | 0.44 | 0.44 | |
Payload Fraction: | 0.13 | 0.13 | |
Aspect Ratio: | 5.76 | 5.80 | |
Loiter L/D: | 22 | 22 | |
Cruise L/D: | 19.1 | 19.1 | |
Cruise Speed (mph): | 560 | 560 | |
Max. Speed (mph): | 630 | 630 | |
Powerplant: | F118-GE-100 | P&W PW800 | |
Max Thrust (lbs): | 19000 | 18000 | |
sfc (lbf/(lbs*hr): | 0.67 | 0.603 | |
W1(lbs): | 141621 | ||
W2 (lbs): | 89351 | ||
Range (SM): | 6900 | 8149 | |
Range (NM): | 6000 | 7082 |
B-2 carries 2xMOP in overload, thats 60,000 lbs50,000 lbs. overload for the B-2
Mr. Wittman said the B21 will have a variant of F135 engine(no reheat)I determined the engine the B-2 would use would most likely be a version of the passport engine, the same one P&W is proposing to re-engine the B-52.
B-2 carries 2xMOP in overload, thats 60,000 lbs50,000 lbs. overload for the B-2
B21 shall carry 1 MOP, so 30k lbs.
Mr. Wittman said the B21 will have a variant of F135 engine(no reheat)I determined the engine the B-2 would use would most likely be a version of the passport engine, the same one P&W is proposing to re-engine the B-52.
HASC member. He stated back in 2018 that B21 would feature modified F135 engines.Who is Mr. Wittman?
Wingspan at 108 ft is too small.Wingspan, b (ft.):172 108
Wingspan at 108 ft is too small.Wingspan, b (ft.):172 108
If payload fraction is assumed to be the identical(due to largely similar shape) and total payload is reduced to 50% of B2, then every dimension of the jet will reduce about 20% (1/2^0.33, since mass∝volume and volume∝dimension³)
As such the wingspan should be about 130-140ft.
In terms of payload carriage, I think it'll feature a single bay the same size as the two on B-2 to make use of existing configurations (using the AF rotary launcher and so on).
Where are your altitude figures? Does the B-21 not have a ceiling significantly higher that B-2? Remember that flutter from much longer wings was part of the risk reduction program. It think that changes your proposed dimensions significantly.My analysis of the B-21 is based off of the first two images shown below; the third is what I generated...... (snip)
Which works out well, as another Aero Engineer who attended school with me and reviewed my work said he figured it should be able to carry one MOAB which weighs around 21,000 lbs.
Dude. Your 20,000 pound payload is not even 8 agm86.My analysis of the B-21 is based off of the first two images shown below; the third is what I generated.
Too much thrust????? Yeah ok, considering that we can safely assume the 21 will need EXCESS thrust for flight control as deflecting surfaces increases RCS. I guess we may as well build a half scale b2 and call it a night.Wingspan at 108 ft is too small.Wingspan, b (ft.):172 108
If payload fraction is assumed to be the identical(due to largely similar shape) and total payload is reduced to 50% of B2, then every dimension of the jet will reduce about 20% (1/2^0.33, since mass∝volume and volume∝dimension³)
As such the wingspan should be about 130-140ft.
In terms of payload carriage, I think it'll feature a single bay the same size as the two on B-2 to make use of existing configurations (using the AF rotary launcher and so on).
OK, I read the article at the drive. The congressman didn't speculate about the engines, the Drive did. Two F-135s would generate too much thrust which would cut into range. I also assumed the design I have shown above would have the same size weapons bay as the B-2, hence half the load. Also, given that it has longer range than the standard B-2, I assume it wouldn't carry as much fuel to carry the MOP, so I'll stick with my original analysis.
Which works out well, as another Aero Engineer who attended school with me and reviewed my work said he figured it should be able to carry one MOAB which weighs around 21,000 lbs.
MOAB is shoved out the back of a C-130, and is not carried by any bomber. MOP (GBU-57), which is carried by the B-52 and B-2, weighs 30,000lbs.
MOAB
View attachment 642335
MOP (GBU-57)
View attachment 642336
Where are your altitude figures? Does the B-21 not have a ceiling significantly higher that B-2? Remember that flutter from much longer wings was part of the risk reduction program. It think that changes your proposed dimensions significantly.My analysis of the B-21 is based off of the first two images shown below; the third is what I generated...... (snip)
But MOP doesn't weigh 21,000lbs. It weighs 30,000lbs.Which works out well, as another Aero Engineer who attended school with me and reviewed my work said he figured it should be able to carry one MOAB which weighs around 21,000 lbs.
MOAB is shoved out the back of a C-130, and is not carried by any bomber. MOP (GBU-57), which is carried by the B-52 and B-2, weighs 30,000lbs.
MOAB
View attachment 642335
MOP (GBU-57)
View attachment 642336
Yeah, meant MOP. Such is life.
I saw figures of 60,000 to 70,000 in one presentation.I assumed it would operate at 50,000 to 55,000 ft.
This is another official planform image. Needless to say it may be pure disinformation with altered proportions as it doesn't match original 2016 rendering.My analysis of the B-21 is based off of the first two images shown below; the third is what I generated.
My understanding is that was Lockheed-Martin, not Northrop-Grumman. But that has to do with structural efficiency by lowering the structural weight of the wing. Also, you don't need high aspect ratio wings for high altitude. You need a large wing area. See the Avro Vulcan. The design I showed above is based off the information released by N-G in the images above, so far. If you have other information actual from them, please provide it. BTW, I assumed it would operate at 50,000 to 55,000 ft.
But MOP doesn't weigh 21,000lbs. It weighs 30,000lbs.
Couldn't the Avro Vulcan fly up at 50-55K??I saw figures of 60,000 to 70,000 in one presentation.I assumed it would operate at 50,000 to 55,000 ft.
I think they threw a blinder over the B-21 size issue by specifying that there be two bays sized to accept a "B-2A Spirit". Looks like the bays will be oversized for the B-21.
Will we with the B-21 finally get a stealth bomber that can dynamically compute engagement/detection ranges and let the crew figure out dynamically how to defeat enemy defenses
Thanks Quellish,Will we with the B-21 finally get a stealth bomber that can dynamically compute engagement/detection ranges and let the crew figure out dynamically how to defeat enemy defenses
B-2 and F-22 already do this, but probably not quite as dynamically as you are envisioning.
Hopefully, Northrop delivers on budget and there are enough B-21's to properly replace the worn out Bones.
This includes authorizer’s approval for full funding of Northrop Grumman’s B-21 stealth bomber, including the first year of procurement funds, the HASC summary said. The Air Force had requested $2.8 billion for Raider R&D, and some $193 million in 2022 to launch procurement of the 100 aircraft the service has said it needs.