Russias next Strategic bomber development

[turin]

Even if its the TU-160 it may not look anything like the TU-160. The structure of the TU-160 is the floor and not the body so it could look drastically different. If its based on the flying wing then things get interesting.

When the Russians go "as far" as saying "based on", then given examples of recent developments (meaning anything post-soviet) this means, its a modified Tu-160. Because if it really would be a new project, involving a new design off the drawing board, the usual language used in Russia involves expressions such as "revolutionary" or "unmatched" etc. The whole thing sounded very down-to-earth when it was announced.

I agree that everything is just speculation at this point in time. But claims involving a completely new design have no grounds in reality. The announced first flight-date of 2015 certainly does not support this (even when the usual Russian optimism is being considered). It would however fit quite well with some modification work being done on the Tu-160 platform.

 

[SpudmanWP]

That is ludicrous for two reasons:

1. It's obvious. There is no way the Tu-160 with RAM treatments could get anywhere near the F-117 which is smaller, was purpose build to be LO, and also has RAM treatments.

2. Since the Russians have never had a pole model to study, they have no idea what the true RCS of the F-117 is. Maybe they can hire Kopp to do a visual study of the F-117? Since they likely have a sample of the RAM from Serbia they would have a better chance at a ball-park number.

 

[PhysicsMan]

When the Russians go "as far" as saying "based on", then given examples of recent developments (meaning anything post-soviet) this means, its a modified Tu-160. Because if it really would be a new project, involving a new design off the drawing board, the usual language used in Russia involves expressions such as "revolutionary" or "unmatched" etc. The whole thing sounded very down-to-earth when it was announced.

I agree that everything is just speculation at this point in time. But claims involving a completely new design have no grounds in reality. The announced first flight-date of 2015 certainly does not support this (even when the usual Russian optimism is being considered). It would however fit quite well with some modification work being done on the Tu-160 platform.

The first PAK DA flight date coincides with the announced date for the start of production of PAK FA. It may be the case that the two are linked technologically. It's possible, for example, they will use 4 AL41F engines on PAK DA which "should" be ready by 2015.

 

[SkolZkiy]

That is ludicrous for two reasons:

1. It's obvious. There is no way the Tu-160 with RAM treatments could get anywhere near the F-117 which is smaller, was purpose build to be LO, and also has RAM treatments.

2. Since the Russians have never had a pole model to study, they have no idea what the true RCS of the F-117 is. Maybe they can hire Kopp to do a visual study of the F-117? Since they likely have a sample of the RAM from Serbia they would have a better chance at a ball-park number.

But may be we have something like F-117 - I mean crashed F-117
Like the one in Iraq or Serbia??

 

[swerve]

2. Since the Russians have never had a pole model to study, they have no idea what the true RCS of the F-117 is. Maybe they can hire Kopp to do a visual study of the F-117? Since they likely have a sample of the RAM from Serbia they would have a better chance at a ball-park number.

Depending on how much co-operation they had from the Serbs, they may have been able to construct a mock up for RCS testing.

 

[PhysicsMan]

Depending on how much co-operation they had from the Serbs, they may have been able to construct a mock up for RCS testing.

Cooperation? Everything the Serbs knew, they knew.

 

[SpudmanWP]

Even if they could duplicate the RAM on the F-117, they would still have a much larger RCS due to shaping and physical size.

 

[PhysicsMan]

Even if they could duplicate the RAM on the F-117, they would still have a much larger RCS due to shaping and physical size.

Yes, they would still need to take care of those large intakes and hide the blades better as well as the exhaust nozzle - probably the biggest noise makers in this configuration. Overall, though, it's a decent shape for a reduced RCS. As for the RAM, they should be able to do much better than F-117 by now - it's a pretty ancient technology on there (assuming F117 still uses the original coating tech).

 

[Bonza]

Even if they could duplicate the RAM on the F-117, they would still have a much larger RCS due to shaping and physical size.

Seconded. While they may have incorporated RCS reducing measures on the Tu-160, the suggestion that an airframe not designed for LO (and that goes for ANY airframe) could attain the same levels of RCS reduction as something like the F-117 just isn't credible.

 

[PhysicsMan]

Seconded. While they may have incorporated RCS reducing measures on the Tu-160, the suggestion that an airframe not designed for LO (and that goes for ANY airframe) could attain the same levels of RCS reduction as something like the F-117 just isn't credible.

There's no such thing as an airframe designed for LO or not. Yes, one can have a plane that totally disregards RCS reduction, but getting a plane to have LO profile is a cumulative effect kind of process, it's not like something is just LO or not LO.
Tu-160 shape was designed with reducing RCS in mind. Statements that something can or cannot achieve this or that result in LO needs to be discussed in terms of concrete changes in design due to the cumulative nature of the reduction process, so unless the only upgrade you're talking about is RAM coating (in that case it wouldn't be as stealthy, of course) the limit is not that well-defined. If they redesign the intakes and nozzles it can be a serious reduction. If they redesign the tail it can be a serious reduction. If they somewhat reshape the wing it can be a serious reduction. If they put a proper cockpit cover on it can be a serious reduction. There are lots of things they can do with the same airframe to reduce RCS a LOT. They say SU-35 frontal RCS is 10 lower than previous Flanker generations, and it was done on the same frame design family.

 

[SpudmanWP]

Sorry to burst you bubble, but the the F-117, B-2, F-22, and F-35 are all designed to be LO (not VLO) irrespective of RAM.

Engine treatments: Such as S-shaped ducts (F-22 and F-35), grills (ala F-117), inlets on the upper wing surface (B-2) all hide the face of the turbines from radar returns.

Internal weapons bays hide the weapons and pylons from radar

Aligned wing and tail edges ensure a vast majority of the radar is reflected away from the transmitter.

Non-vertical tail surfaces

Very smooth surfaces

No external antenna elements

Hidden engine exhausts (B-2 and F-117)

Angled engine exausts (F-22 and F-35)

Absolutely NO edge that is perpendicular to the plane of travel.

Treated canopies

These items, and much more, contribute the greatest to lowering the RCS and NONE of them deal with RAM coatings.

 

[Bonza]

There's no such thing as an airframe designed for LO or not. Yes, one can have a plane that totally disregards RCS reduction, but getting a plane to have LO profile is a cumulative effect kind of process, it's not like something is just LO or not LO.
Tu-160 shape was designed with reducing RCS in mind. Statements that something can or cannot achieve this or that result in LO needs to be discussed in terms of concrete changes in design due to the cumulative nature of the reduction process, so unless the only upgrade you're talking about is RAM coating (in that case it wouldn't be as stealthy, of course) the limit is not that well-defined. If they redesign the intakes and nozzles it can be a serious reduction. If they redesign the tail it can be a serious reduction. If they somewhat reshape the wing it can be a serious reduction. If they put a proper cockpit cover on it can be a serious reduction. There are lots of things they can do with the same airframe to reduce RCS a LOT. They say SU-35 frontal RCS is 10 lower than previous Flanker generations, and it was done on the same frame design family.

When you say there's no such thing as an airframe designed for low observability, what then would you call the F-117 airframe? It made serious concessions to aerodynamic performance with the specific intention of reducing radar cross section, how is this anything but being designed for low observability?

I agree with you that it's a cumulative process with a variety of contributing factors. Maybe my post could have been worded better.

My point was that while measures such as the ones you've outlined above will of course decrease the RCS of a given platform, this does not necessarily mean said platform will attain the same levels of low observability enjoyed by something like the F-117, or any of the dedicated "stealth" platforms. Because I'd argue these dedicated platforms have a high degree of LO inherent in their design, rather than something like a Tu-160, which while it may incorporate RCS reducing measures, is clearly not a "stealthy" airframe (by comparison, of course).

Please take this in the context of the specific example I made (the Tu-160's RCS as compared to the F-117). Surely you can see a more dedicated level of concessions made to low observability in one rather than the other.

I apologise if my choice of words was poor and while I agree with you that it's not nearly as simple as "LO or not LO" (and I didn't mean to give that impression), I would debate your point that there's no such thing as an airframe designed for low observability. The F-117, B-2, F-22 and F-35 (and the PAK-FA, whenever it shows up) all have a design goal of high levels of RCS reduction, accomplished through various means, and thus they have been designed as LO airframes.

 

[PhysicsMan]

Sorry to burst you bubble, but the the F-117, B-2, F-22, and F-35 are all designed to be LO (not VLO) irrespective of RAM.

Engine treatments: Such as S-shaped ducts (F-22 and F-35), grills (ala F-117), inlets on the upper wing surface (B-2) all hide the face of the turbines from radar returns.

Internal weapons bays hide the weapons and pylons from radar

Aligned wing and tail edges ensure a vast majority of the radar is reflected away from the transmitter.

Non-vertical tail surfaces

Very smooth surfaces

No external antenna elements

Hidden engine exhausts (B-2 and F-117)

Angled engine exausts (F-22 and F-35)

Absolutely NO edge that is perpendicular to the plane of travel.

Treated canopies

These items, and much more, contribute the greatest to lowering the RCS and NONE of them deal with RAM coatings.

Apparently you missed the meaning of what I wrote. I said that planes aren't designed LO by some definition or a magic formula, meaning that it's a continual process, with components among which are the things you listed. If you take away any of the above design features from any of those planes they will still be LO in most directions, just incrementally reduced in some. Same (or reverse, I should say) goes for adding such features to an aircraft that already has some features reducing its RCS.

 

[Bonza]

Apparently you missed the meaning of what I wrote. I said that planes aren't designed LO by some definition or a magic formula, meaning that it's a continual process, with components among which are the things you listed. If you take away any of the above design features from any of those planes they will still be LO in most directions, just incrementally reduced in some. Same (or reverse, I should say) goes for adding such features to an aircraft that already has some features reducing its RCS.

Ah, I think I misunderstood some of what you said as well, apologies for that. However a point I would make regarding the addition of LO features to a pre-existing airframe is that it is not necessarily possible depending on the specific feature.

To go back to the previous example I made, adding the LO features inherent to the F-117's airframe (shaping etc), and thus intrinsic to its RCS reduction, would not necessarily be possible on an airframe such as the Tu-160 without massive changes to the airframe itself (to the point where it would be a new design rather than an existing one).

My contention was based on the report mentioned earlier in the thread, which references upgrades to the Tu-160 such that it attained a level of LO equal to the F-117. I seriously doubt upgrades would be able to provide this comprehensive a level of LO, due to intrinsic differences in the airframes and indeed design goals of the two platforms.

I think we're talking at cross purposes here anyway, and I do apologise for misinterpreting some of what you said.

 

[PhysicsMan]

Ah, I think I misunderstood some of what you said as well, apologies for that. However a point I would make regarding the addition of LO features to a pre-existing airframe is that it is not necessarily possible depending on the specific feature.

To go back to the previous example I made, adding the LO features inherent to the F-117's airframe (shaping etc), and thus intrinsic to its RCS reduction, would not necessarily be possible on an airframe such as the Tu-160 without massive changes to the airframe itself (to the point where it would be a new design rather than an existing one).

My contention was based on the report mentioned earlier in the thread, which references upgrades to the Tu-160 such that it attained a level of LO equal to the F-117. I seriously doubt upgrades would be able to provide this comprehensive a level of LO, due to intrinsic differences in the airframes and indeed design goals of the two platforms.

I think we're talking at cross purposes here anyway, and I do apologise for misinterpreting some of what you said.

You bring this discussion to where it should have headed from the beginning - whether it's possible to incorporate significant RCS reducing airframe changes to the existing design of TU-160.
It seems to me that at least some important steps are very doable from engineering and monetary point of view. Redesigning the engine intakes and exhaust nozzles seems to me like one of such steps. Another one that should be simpler (but very important) is swapping the existing canopy glass with one that can't be easily penetrated by radar radiation. The overall shape of the airframe already has some really important LO features - it has a very flat bottom side (minus the engines) that has the wings in the same plane; the nose is flattened (they could sharpen the edges more); the overall shape is very smooth and continuous, with the top not making too many reflective angles either. The wings extend smoothly from the nose, they could probably try to even make it a straight line (tough?..). A big one is the tail shape - I don't know if it's possible to do anything about the perpendicular planes that it makes but I bet it's not an impossible task either. If these things are done plus an advanced RAM coating, I wouldn't bet money on TU-160 being much larger than F-117 in RCS in certain directions. It won't be anywhere near F-22 or B-2 but from what I've read F-117 is not at that level...

 

[Bonza]

You bring this discussion to where it should have headed from the beginning - whether it's possible to incorporate significant RCS reducing airframe changes to the existing design of TU-160.
It seems to me that at least some important steps are very doable from engineering and monetary point of view. Redesigning the engine intakes and exhaust nozzles seems to me like one of such steps. Another one that should be simpler (but very important) is swapping the existing canopy glass with one that can't be easily penetrated by radar radiation. The overall shape of the airframe already has some really important LO features - it has a very flat bottom side (minus the engines) that has the wings in the same plane; the nose is flattened (they could sharpen the edges more); the overall shape is very smooth and continuous, with the top not making too many reflective angles either. The wings extend smoothly from the nose, they could probably try to even make it a straight line (tough?..). A big one is the tail shape - I don't know if it's possible to do anything about the perpendicular planes that it makes but I bet it's not an impossible task either. If these things are done plus an advanced RAM coating, I wouldn't bet money on TU-160 being much larger than F-117 in RCS in certain directions. It won't be anywhere near F-22 or B-2 but from what I've read F-117 is not at that level...

From what I understand, and for the reasons I've stated previously, I don't think you'd be able to get that level of RCS reduction out of the Tu-160 - there just doesn't seem to be the necessary shaping or design intent in the airframe as it exists now. Keep in mind that even loose screws on the F-117's airframe, during tests, increased RCS incredibly. Now imagine what the engines of the Tu-160 are going to do to the RCS of the otherwise relatively flat bottom...

Another sticking point for me is the idea of directional RCS reduction. I would think in order to attain LO "comparable to the F-117" you would by association be talking about all-aspect LO...however I realise that may be open to interpretation and is only my opinion.

It would be good to get the input of one of the more knowledgeable posters - GF, are you around? Assuming you're not sick to death of answering LO related questions by this point...

 

[PhysicsMan]

From what I understand, and for the reasons I've stated previously, I don't think you'd be able to get that level of RCS reduction out of the Tu-160 - there just doesn't seem to be the necessary shaping or design intent in the airframe as it exists now. Keep in mind that even loose screws on the F-117's airframe, during tests, increased RCS incredibly. Now imagine what the engines of the Tu-160 are going to do to the RCS of the otherwise relatively flat bottom...

Another sticking point for me is the idea of directional RCS reduction. I would think in order to attain LO "comparable to the F-117" you would by association be talking about all-aspect LO...however I realise that may be open to interpretation and is only my opinion.

It would be good to get the input of one of the more knowledgeable posters - GF, are you around? Assuming you're not sick to death of answering LO related questions by this point...

You may be right, too bad we don't have hard data on these planes...
On the directional RCS reduction... It has to be an important factor since the radar beam always comes from a certain direction. This should be particularly important for a long range cruise missiles-carrying bomber like Tu-160, which strikes from a long range - it's essential to be able to detect it (and avoid detection on the opposite end) from an even longer distance, and that would be a frontal illumination, hence the frontal RCS should be particularly important for such aircraft...

 

[Feanor]

The key thing though is that the new Tu-160s have not seen any major airframe redesigning. In fact the "new" Tu-160s so far have been assembled mostly from parts left in factory stocks from the Soviet days.

Granted there is currently a modernization program underway, that replaces the engines, and upgrades the avionics. But it's also not doing anything to the airframe shape.

 

[vivian]

that's a long long journey for russia to do that .