Dragon029 said:
I'm not sure if they count as metamaterials, but Lockheed's work with variably-doped carbon nanotubes has supposedly yielded broadband blackbody composites. Northrop could have something similar, though I'm not confident that they'd be used due to the probable higher costs involved.

....and here is Lockheed Martin's patent!

 
Ian33 said:
bobbymike said:
https://www.defensetech.org/2017/03/17/first-rule-b-21-not-talk-b-21/?ESRC=deftech.sm

Agreed 100%

Payload, engines, inlet design, exhausts, the whole shebang should be hidden until it has to break cover. Heck, I still don't believe it is a flying wing ala B2, but that's just me.

Maybe people like yourself who seem keen to cover up everything including the costs are probably the same people that thought programs like the F-35 should have a blank cheque with taxpayers money. And before you say well politicians are overlooking stuff like that, I don't think that's particularly reassuring these days considering the standard of the modern occupier of such positions.
 
The modern statutory and oversight environment for acknowledged Special Access Programs (e.g. B-21)
is substantially different from most of the period during which ATB was under development.

Under the modern regime, the Air Force has never denied access to members of Congress who
had the approval of the chair and ranking member of the relevant defense committees.

And unlike most of the ATB period, the politicians with access will be reading the red team/blue team,
Special Access DAB and other independent assessments.
 
Ian33 said:
bobbymike said:
https://www.defensetech.org/2017/03/17/first-rule-b-21-not-talk-b-21/?ESRC=deftech.sm

Agreed 100%

Payload, engines, inlet design, exhausts, the whole shebang should be hidden until it has to break cover. Heck, I still don't believe it is a flying wing ala B2, but that's just me.

On what grounds? Unless you're hoping for higher speeds, its hard to see why it wouldn't be a flying wing.
 
Flyaway said:
Maybe people like yourself who seem keen to cover up everything including the costs are probably the same people that thought programs like the F-35 should have a blank cheque with taxpayers money.

But you know what happens when the public gets too much development information? You wind up with people freaking out over routine development issues and declaring the program to be a "miserable failure" because a crack was discovered on the fatigue test article or a bug was found in the software.
 
gtg947h said:
Flyaway said:
Maybe people like yourself who seem keen to cover up everything including the costs are probably the same people that thought programs like the F-35 should have a blank cheque with taxpayers money.

But you know what happens when the public gets too much development information? You wind up with people freaking out over routine development issues and declaring the program to be a "miserable failure" because a crack was discovered on the fatigue test article or a bug was found in the software.

This. Monday-morning quarterbacking by hoards of imbeciles, and then the politicians freak out / try to make a name on killing the program.
 
PaulMM (Overscan) said:
Ian33 said:
bobbymike said:
https://www.defensetech.org/2017/03/17/first-rule-b-21-not-talk-b-21/?ESRC=deftech.sm

Agreed 100%

Payload, engines, inlet design, exhausts, the whole shebang should be hidden until it has to break cover. Heck, I still don't believe it is a flying wing ala B2, but that's just me.

On what grounds? Unless you're hoping for higher speeds, its hard to see why it wouldn't be a flying wing.

Lockheed bomber design (Not QUARTZ, the faceted almost X47b design) The X47b itself, the NGB from Northrop being a manned cranked design... something just tells me that this will be a better scoot and shoot than what the pure flying wing could offer.
 
Boeing/LM NGB/2018 Bomber design _was_ also a flying wing almost indistinguishable from _officially_ declassified LRS-B/B-21 flying wing design.
Where's your logic?
 
Ian33 said:
PaulMM (Overscan) said:
Ian33 said:
bobbymike said:
https://www.defensetech.org/2017/03/17/first-rule-b-21-not-talk-b-21/?ESRC=deftech.sm

Agreed 100%

Payload, engines, inlet design, exhausts, the whole shebang should be hidden until it has to break cover. Heck, I still don't believe it is a flying wing ala B2, but that's just me.

On what grounds? Unless you're hoping for higher speeds, its hard to see why it wouldn't be a flying wing.

Lockheed bomber design (Not QUARTZ, the faceted almost X47b design) The X47b itself, the NGB from Northrop being a manned cranked design... something just tells me that this will be a better scoot and shoot than what the pure flying wing could offer.

Scoot and shoot? Its not a tactical fighter like a 35 or Strike Eagle. It will optimized for low drag to decrease fuel consumption. It will be optimized for stealth across multiple frequencies. It does not need to maneuver like a Bone and perform aileron rolls. It will be a flying wing. It will have standoff weapons and a new ALCM. Whether or not the rear of the Raider is going to be serrated like the Spirit or a simple W like the original B2 design was intended is the question. The other question is how many engines will it have. I think more than 2. With 2 engines, and one fails, a heavy bomber probably won't make it home on just 1.
 
For AFRL's Long Range Strike subsonic profile, Lt. Col Simmons' PhD dissertation

"Design and control of a variable geometry turbofan with and independently modulated third stream"

models a twin engine configuration with takeoff military thrust of 30,000 lbs /engine, BPR of 1.86 and a max fan diameter of 56 inches.
 

Attachments

  • simmons-lrs-subsonic.png
    simmons-lrs-subsonic.png
    280.1 KB · Views: 445
  • simmon-payload-range-tradeoff.png
    simmon-payload-range-tradeoff.png
    256.1 KB · Views: 435
marauder2048 said:
For AFRL's Long Range Strike subsonic profile, Lt. Col Simmons' PhD dissertation

"Design and control of a variable geometry turbofan with and independently modulated third stream"

models a twin engine configuration with takeoff military thrust of 30,000 lbs /engine, BPR of 1.86 and a max fan diameter of 56 inches.

Oh that pic reminded me of the unknown seen by Steve Douglas.
 

Attachments

  • images-16.jpg
    images-16.jpg
    8.1 KB · Views: 554
Airplane said:
Ian33 said:
PaulMM (Overscan) said:
Ian33 said:
bobbymike said:
https://www.defensetech.org/2017/03/17/first-rule-b-21-not-talk-b-21/?ESRC=deftech.sm

Agreed 100%

Payload, engines, inlet design, exhausts, the whole shebang should be hidden until it has to break cover. Heck, I still don't believe it is a flying wing ala B2, but that's just me.

On what grounds? Unless you're hoping for higher speeds, its hard to see why it wouldn't be a flying wing.

Lockheed bomber design (Not QUARTZ, the faceted almost X47b design) The X47b itself, the NGB from Northrop being a manned cranked design... something just tells me that this will be a better scoot and shoot than what the pure flying wing could offer.

Scoot and shoot? Its not a tactical fighter like a 35 or Strike Eagle. It will optimized for low drag to decrease fuel consumption. It will be optimized for stealth across multiple frequencies. It does not need to maneuver like a Bone and perform aileron rolls. It will be a flying wing. It will have standoff weapons and a new ALCM. Whether or not the rear of the Raider is going to be serrated like the Spirit or a simple W like the original B2 design was intended is the question. The other question is how many engines will it have. I think more than 2. With 2 engines, and one fails, a heavy bomber probably won't make it home on just 1.

2 ADVENT engines from General Electric? I mean, they had those ready for a bomber application back in 2014 IIRC. Would those not suffice?
 
Ian33 said:
2 ADVENT engines from General Electric? I mean, they had those ready for a bomber application back in 2014 IIRC.
Yes, in some alternative universe.
 
flateric said:
Ian33 said:
2 ADVENT engines from General Electric? I mean, they had those ready for a bomber application back in 2014 IIRC.
Yes, in some alternative universe.

I believe Ian33 is referring to this:

'GE currently has a full ADVENT engine in testing that is designed for a “bomber application,” says spokesman Matt Benvie.'

I believe this refers to the ADVENT demonstrator engine, which is not quite the same as a finished engine. The USAF likely went for a less risky development of the F135 from Pratt & Whitney, and have already announced P&W are the engine contractor.
 
In fact with the steve Douglass photography and after 3 years we still don't know what are this aircraft ???
 
PaulMM (Overscan) said:
I believe this refers to the ADVENT demonstrator engine, which is not quite the same as a finished engine. The USAF likely went for a less risky development of the F135 from Pratt & Whitney, and have already announced P&W are the engine contractor.

From what's been disclosed about the F135 low spool + GTF core PW9000, it broadly meets the "Advanced Turbofan" spec i.e. the blue line in the payload-range figure.
 
But why would the B-21 be anything other than a high-altitude all-aspect stealth bomber? There's no reason for it to have a low-altitude penetration capability.
 
DrRansom said:
But why would the B-21 be anything other than a high-altitude all-aspect stealth bomber? There's no reason for it to have a low-altitude penetration capability.

Laydown delivery
 
marauder2048 said:
DrRansom said:
But why would the B-21 be anything other than a high-altitude all-aspect stealth bomber? There's no reason for it to have a low-altitude penetration capability.

Laydown delivery

There have to be better ways to get surface or sub-surface bursts these days.
 
TomS said:
marauder2048 said:
DrRansom said:
But why would the B-21 be anything other than a high-altitude all-aspect stealth bomber? There's no reason for it to have a low-altitude penetration capability.

Laydown delivery

There have to be better ways to get surface or sub-surface bursts these days.

Not in the US. In fact we have far fewer options than we have in the past, especially if you need something more than a couple dozen kilotons.
 
Point being, if that delivery profile were needed (debatable) there are easier ways to get there than to design a whole aircraft to accomplish a laydown delivery.
 
TomS said:
Point being, if that delivery profile were needed (debatable) there are easier ways to get there than to design a whole aircraft to accomplish a laydown delivery.

Not if the past is any indicator. How many decades has it been since we've since we designed a new cruise missile with a megaton+ warhead? Our design/acquisition process is so FUBARED I'd be astonished if we could even do a clean-sheet Tomahawk replacement, let alone anything useful. If you want to be able to laydown a B83 over intercontinental distances a bomber is your only realistic choice. (Sure, we can think of dozens of alternatives, none of which are anymore likely in the US than finding a crock of leprechaun gold. Fasthawk, RATTLRS, HyFly etc. would have been perfect and we all saw what happened there - a whole lot of nothing.)
 
I thought that the latest B-61 mod didn't require laydown for penetrating effect? I.e. it is hardened to penetrate deep enough to couple nuclear blast with the earth.

Also, if laydown is needed, then a wing kit could be added to the bomb. Better that than make the B-21 be overbuilt like the B-2.
 
DrRansom said:
I thought that the latest B-61 mod didn't require laydown for penetrating effect? I.e. it is hardened to penetrate deep enough to couple nuclear blast with the earth.

Also, if laydown is needed, then a wing kit could be added to the bomb. Better that than make the B-21 be overbuilt like the B-2.

Such a bomb wouldn't be stealthy and could easily be shot down by TOR and the like. A terrain following JASSM-ER with a W83 or W80 might be the ticket though. Of course you still need the bomber to get it there.
 
Exactly. B61-11 and -12 have both shown earth-penetrating capability, which is the main purpose behind laydown. So you can deliver modern weapons from high level and get the hard-target effect desired without the demanding flight profile of a laydown delivery.

SFerrin, I wonder if you're equating "laydown" with any nuke delivered by a bomber. It's not. Laydown is the very particular delivery profile where the bomb lands and then detonates a short time later. It's very fiddly, requires a low-level delivery and specialized weapons, and is useful only for a few specific target types.
 
TomS said:
SFerrin, I wonder if you're equating "laydown" with any nuke delivered by a bomber. It's not. Laydown is the very particular delivery profile where the bomb lands and then detonates a short time later. It's very fiddly, requires a low-level delivery and specialized weapons, and is useful only for a few specific target types.

I know exactly what "laydown" means. (A shame we cancelled the B77.)
 
Then why are you so insistent that we need it when there are other, easier, ways to achieve the same effect?
 
TomS said:
Then why are you so insistent that we need it when there are other, easier, ways to achieve the same effect?

Those "easier" ways don't exist. MAYBE a cruise missile could be made to do the job but is there a program to even develop one that can? An F-35 could probably do it but they don't plan on clearing it with the B83 so that option's out.
 
If there is a Tor at the target site, then no weapon is getting through with any certainty, including JASSM. And certainly no aircraft at low level is surviving either.

The problem of a point-defended target is not solved yet by any USAF weapon system. It will be in time, but until then, compromising the B-21 for lay down is a waste of money.
 
DrRansom said:
If there is a Tor at the target site, then no weapon is getting through with any certainty, including JASSM. And certainly no aircraft at low level is surviving either.

Load up JASSM with submunitions, or use JSOW. It's not going to be shooting down submunitions.
 
sferrin said:
DrRansom said:
If there is a Tor at the target site, then no weapon is getting through with any certainty, including JASSM. And certainly no aircraft at low level is surviving either.

Load up JASSM with submunitions, or use JSOW. It's not going to be shooting down submunitions.

I thought we were discussing nuclear strike?
 
With the picture available of the B-21 it look more of high altitude cruiser than a low cruiser, the first B-2 iteration for high altitude with no cranked tail was the same design of the actual B-21. The cranked tail was for the low altitude capacity.
 
I suspect that the B-21 won't work in isolation and any strike on a hardened target that is point defended will first be serviced by a ICBM RV used in a SEAD role.
 
DrRansom said:
I thought we were discussing nuclear strike?

No reason you couldn't have a couple missiles with submunitions helping the nuke get through.
 
sferrin said:
Those "easier" ways don't exist. MAYBE a cruise missile could be made to do the job but is there a program to even develop one that can? An F-35 could probably do it but they don't plan on clearing it with the B83 so that option's out.

That's precisely what LRSO is about, isn't it?
 
TomS said:
sferrin said:
Those "easier" ways don't exist. MAYBE a cruise missile could be made to do the job but is there a program to even develop one that can? An F-35 could probably do it but they don't plan on clearing it with the B83 so that option's out.

That's precisely what LRSO is about, isn't it?

AFAIK they plan on scraping the rust off a bunch of old W80s. No W83 in the works. Assuming LRSO doesn't get cancelled.
 

Similar threads

Back
Top Bottom