Northrop Grumman B-21 Raider (LRS-B)

[Flyaway]

And here come the politicians.

"I am pleased that after years of delays, we are back on track to acquiring this critical capability. Our nation needs a large fleet of next-generation bombers, so this critical program deserves Congress’ close scrutiny as well as its strong support,” said Rep. J. Randy Forbes (R-Va.), chairman of the House Armed Services’ Seapower and Projection Forces subcommittee in a statement after the release of the B-21’s official designation.

https://www.washingtonpost.com/news/checkpoint/wp/2016/02/26/air-force-releases-first-image-of-its-new-long-range-bomber/

As I said above the concept I imagine is altered to hide details such as the inlets and outlets not the overall concept.

 

[flateric]

Payback for Chadwick

Challenges Await New Boeing Defense Head

When Leanne Caret assumes the leadership of Boeing’s defense on March 1, substantial challenges will be waiting.

www.defensenews.com

 

[skyblue]

Only 21 B-2 bombers were built.

Is the designation B-'21' a reminder to not make the same mistake?

 

[Steve Pace]

I was expecting more than a B-2 look-a-like (well almost) but I guess as the old adage goes, "If it isn't broke, don't fix it," holds true in this case. Still...
-SP

 

[NeilChapman]

Are there any advantages to the "wing" vs "cranked-kite"? Is it possible that NG has "learned" more about how to optimize the wing such that that cranked-kite isn't desirable for performance envelope of this plane?

The cranked kite is a compromise between a diamond (X-47) and a flying wing. The diamond shape has very good LO characteristics but sacrifices payload and handling. This made it a less than ideal choice for a carrier based strike aircraft. A flying wing also has very good LO characteristics, has good payload and range, but is not idea for carrier operations (for a number of reasons). Thus, the cranked kite. Not so good on the LO, but you can use it on a carrier.

Thank you quellish! As this is not a carrier-based aircraft the cranked-kite may not have been necessary?

 

[hesham]

Hi,

give me essential differences between it and B-2 ?.

 

[flateric]

...

 

[overscan (PaulMM)]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

 

[Sundog]

McCain threatens to block the LRSB

 

[Grey Havoc]

Over at HP&CA, they are wondering whether there was a foul-up somewhere along the line, and the actual designation is supposed to be the B-2I.

 

[sublight_]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

Except VHF.

 

[overscan (PaulMM)]

Foxtrot Alpha posted this logo with their story. Agree with the planform sweep?

 

[overscan (PaulMM)]

Oh and - regarding "cranked wing" - look at the J-10 wing from the front. Looks cranked, but it isn't.

 

[Jeb]

The line seems to be that we're specifically not looking at major technological advances in capability, but in affordability. That's why it looks like the B-2; they took a proven concept and made it cheaper.

That makes a lot of sense, so i doubt that's the path they would have chosen.

In the meanwhile i took the liberty to correct their picture...


Regards.

HAH! B-2.1. It took me a minute to spot that.

 

[Bill Walker]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

And Northrop hit the one optimal shape on their first try?

 

[overscan (PaulMM)]

Intakes look like X-47B. I think the sweep angle will be 40 degrees, not 45 as shown in the Foxtrot Alpha drawing.

 

[sferrin]

The more I look at it the more it makes me think of the LM Polecat.

 

[overscan (PaulMM)]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

And Northrop hit the one optimal shape on their first try?

For reference - this Boeing Lockheed subsonic NGB design is its separated-at-birth twin.

 

[overscan (PaulMM)]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

And Northrop hit the one optimal shape on their first try?

Pretty much, yes. For reference - this Boeing Lockheed subsonic NGB design is its separated-at-birth twin. If this is in any way similar to the design Boeing offered, then it really was a repeat of the ATB competition.

There's not much you can improve on for a subsonic 4 lobe RCS design.

 

[Orionblamblam]

Foxtrot Alpha posted this logo with their story. Agree with the planform sweep?

It sure doesn't look right. But at this stage, it's impossible to. Remember the introduction to the F-117? Depending on how you present an image, you can really mess with peoples assessment of angles.

And of course, this being an artists impression, it could be intentionally wrong.

 

[quellish]

Except VHF.

No.

 

[quellish]

Foxtrot Alpha posted this logo with their story. Agree with the planform sweep?

I am very surprised no forum member has done a 3D model yet.

 

[sferrin]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

And Northrop hit the one optimal shape on their first try?

Pretty much, yes. For reference - this Boeing Lockheed subsonic NGB design is its separated-at-birth twin. If this is in any way similar to the design Boeing offered, then it really was a repeat of the ATB competition.

There's not much you can improve on for a subsonic 4 lobe RCS design.

Consider also what the B-2 looked like before they added the low altitude requirement.

 

[Steve Pace]

The more I look at it the more it makes me think of the LM Polecat.

Or the NG RQ-180. -SP

 

[sferrin]

The more I look at it the more it makes me think of the LM Polecat.

Or the NG RQ-180. -SP

Was there ever an "official" released picture of that? ???

 

[sublight_]

Except VHF.

No.

No what?

 

[stealthflanker]

No what?

Well just look at those long leading and trailing edges. Those must still be in realm of optical scattering regime even in VHF. Still able to direct the specular lobe somewhere else and presenting the weaker lobe to the radar.

 

[quellish]

No what?

OK, Paul said:

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

To which you replied:

Except VHF.

Which is not correct.
Paul later ellaborated:

There's not much you can improve on for a subsonic 4 lobe RCS design.

A heavy bomber is more or less stuck with a 4-lobe "bowtie" RCS because of mission requirements. Large payload, long distance, etc. A 3-lobe "OMG NINJAS" RCS on it's surface looks like desirable. A triangular object can have a 3-lobed RCS, like the A-12. Depending on the polarization though the 3-lobe RCS can be a huge disadvantage (like, again, the A-12). Most modern 4-lobe RCS designs are largely consistent across different polarizations. A well designed diamond shape (like the X-47A) has the best attributes of both with few of the disadvantages. It does not work for a heavy bomber though.

VHF, UHF, WiFi, EBS, has nothing to do with that.

 

[Steve Pace]

If you take a straight edge and superimpose it onto the leading- and trailing-edges on the B-2 you'll see that they curve in and out toward each apex. The "new" B-2 design has fewer trailing-edges. -SP

 

[overscan (PaulMM)]

Worth reading through this 2008 paper by Northrop Grumman on the case for the 2018 (i.e. near term) bomber.

http://www.northropgrumman.com/AboutUs/AnalysisCenter/Documents/pdfs/The_2018_Bomber_the_case_for_a.pdf

Seems fairly relevant to topic.

 

[Flyaway]

Mr Sweetman has had his say but unfortunately the article needs registration for access.

Meet the B-21 Bomber, Formerly Known As LRS-B | Aviation Week Network

Air Force Secretary Deborah James revealed a concept drawing of the new U.S. bomber, which will be built by Northrop Grumman.

aviationweek.com

 

[overscan (PaulMM)]

You could always register and read it. Its free.

 

[overscan (PaulMM)]

Trawling through mountains of old Northrop-Grumman artwork, this one seemed interesting.

 

[dark sidius]

Wher do you find this design in 2011 ?

 

[RadicalDisconnect]

Why did low altitude penetration require the additional trailing edge serration?

 

[flateric]

Why did low altitude penetration require the additional trailing edge serration?

http://www.northropgrumman.com/Capabilities/B2SpiritBomber/Documents/pageDocuments/B-2-Spirit-of-Innovation.pdf

 

[flateric]

Wher do you find this design in 2011 ?

I've found it in one of NASA ERA powerpoints

 

[RadicalDisconnect]

Why did low altitude penetration require the additional trailing edge serration?

http://www.northropgrumman.com/Capabilities/B2SpiritBomber/Documents/pageDocuments/B-2-Spirit-of-Innovation.pdf

page 55 ->

Great read, thank you.

 

[hesham]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

My dear Paul,

that means the USA developed a future bomber with only distinguish,a modern Shape,and almost
small benefits rather than B-2 ?.

 

[Flyaway]

Due to the laws of physics, this is a pretty much optimal shape for lowest possible RCS on a subsonic platform.

My dear Paul,

that means the USA developed a future bomber with only distinguish,a modern Shape,and almost
small benefits rather than B-2 ?.

It would be foolish to think that just because they look similar that they are anything that alike in reality.