Wingman said:That's one of the reasons why the B2 is so expensive! Flying wings are a radical design and are very difficult and expensive to develop and test.
One of the reasons, yes. But by far not the biggest reason. Just like US did, one has to take several steps to get to true flying wing. If you read my initial post here you will see i proposed a blended wing desing, something akin to avro vulcan, as a first step. First flying wings were expensive cause they were exactly that - first. It is not a revolutionary tech anymore and it will be even less so in 20 - 25 years by which time the blended wing design would fully give way to a true flying wing.
Wingman said:Think of it as this way. Take your fat slow non-swing wing bomber and give it the ability to sweep its wings. It gains the ability to fly faster and everything else stays essentially the same.
I don't agree. Flying wing is thicker and using swing wing on it would be a huge undertaking. The space lost and weight waisted would be tremendous. And stealth would suffer more than you think. One of the big reasons why f117 and b2 have lowered RCS is cause they have a relatively smooth, flat undersides, without any gaps in the airframe. Of course, for that to be maximized, they fly high, so the enemy large radar's beams come from a lower angle.
Wingman said:No it won't lose lift because higher speed produces higher lift. No it won't be able to carry less payload because it won't lose lift. No it won't lose fuel efficiency, in fact it will gain fuel efficiency because of lower drag!!
Once again, higher speed is used a small portion of the time in long range missions. All the swing wing bombers cruise under the speed of sound, with wings swept more forward. If they went faster, drag would increase immensely and fuel efficiency would drop sharply. At same subsonic speed, a more conventional fuselage with swept wing design, compared to a flying wing of same wingspan suffers more drag. Only when going at higher speeds does drag increase more for the thicker flying wing design then for the more conventional design. Also, it is not important if you can get lift for 200 tons at speed of mach 2, what is important is what lift you can get at take off speed, or at best, at in-air-refualling speed. Keep in mind air density also affects lift, the higher you go, less lift you will get. So basically at a given high altitude you have to either go fast or have a wing design that will give you more lift. And no, less air density doesnt give enough of a drag relief to make it worthy to fly fast, otherwise you'd have tu160, tu22, lancer etc cruise at 2 mach normally, 100% of their flight time.
Wingman said:No it won't become less stealthy (at least not by much). Unless you have a multi-billion-dollar-flying-wing-stealth-bomber it doesn't make any difference if you lose a little bit of stealth.
You say it wont lower the RCS by much, i say it will. I guess we disagree on that one beyond any way to reason with each other. Besides, every little bit of stealth helps. Of course it would be silly to embark on a expensive maximize-the-stealth project like B2 was back in the 80s, but as stealth tech is more common and more known, it does get cheaper to apply it. So while the chinese bomber might be have like 150% of B2s RCS, it will have that for 10% of the price.
Wingman said:It does make a lot of difference if your bomber slow, because that makes it a lot more vulnerable. Most swing-wing bombers can fly at Mach 2, enough to outrun fighters and get the hell back home in one piece.
It makes it more vulnerable, yes. Which is why i also said it wouldnt hurt to make it a multi purpose platform. Sure, in a dogfight it wouldn't have a chance but it could easely be fitten with long rang BVR missiles. With it being more stealthy than attacking fighter planes - it'd have a fair chance. And of course im not proposing to go over the target to drop bombs. It would be more of a stand off weapon launch platform. When a day comes that its economically and technically feasible to use just cruise missiles to go around the world - bombers will cease to exist. Until that time comes, having a bomber carry shorter range cruise missiles is the way to go.
Wingman said:As for one big bomber vs. multiple smaller fighter-bombers, that one big bomber is going to be a lot less survivable than the fighter-bombers. If a missile comes at you from long range, you need to turn away from it and run. Bombers need like half a minute to do just that, and by that time they're dead. Fighter-bombers are more manoeuvrable and therefore can avoid missiles more easily.
stealth adds to survivability. stealth requires internal stores. internal stores require lots of space. lots of space require a large airplane. large airplane carrying ground attack missiles is called a bomber. But thats even a secondary point. Main point for a bomber is range. how will you get your small-ish fighter bomber to fly half around the world? Of course if your doing a short range mission youll use attack planes. But the bomber remains the only option for intercontinental missions. Notice how i said getting the su34 would be a good idea for china as it just starts developing the bombers? its cause right now china has less need for intercontinental strikes. but that may change with time and as that need rises, it is only smart to have a long range bomber developed.