Chinese Hypersonic Developments (HGVs/HCMs)

escobar said:

Faithful?? What i mean IS almost no one ever doubt over the good df-Zf cep claim but now some have doubt on this.

Click to expand...

Df-zf is operational, why doubt it?
There are many reasons why one would accept one but doubt the other. On the other hand, there are many reasons too one tell truth for one thing but not for another. Once a truth teller always a truth teller? It doesn't work that way.

There is a lot of typical expected deception with these things. The 24 miles out claim by FT is not verified by anything official. It could or may not be actual fact.

If it isn't an actual fact, then we simply don't know anything about it, it could have great CEP, it could be even more far out and inaccurate than 24 miles.

If it is an actual fact, ask how they would even know where the true intended target is. There is no indication that what an intelligence observer thinks is the intended target, actually is the intended target. Then there's the entirely possible (in fact extremely likely) case that this test intentionally needed to feed some misinformation and/or disinformation with regards to "intelligence" reports passed on to the Americans or sources considered American associated within China or elsewhere. Either direct misinformation with misdirection of target to avoid giving further details. Actual target (if any for this test) would have been genuinely kept secret to physical observation, and fed incorrectly as disinformation to intelligence gathering.

Then there's the final and most important aspect. The US always plays both ends, simultaneously creating the fear factor and how China's a threat etc etc while also denigrating. Typically it's in the form of "they're trying to do this amazing xyz and look how they failed in abc ways". So while they need to report on this test and use that as a means of promoting US MIC and getting funding by playing up threat etc (note that none of these things are for peacetime use so US need only not attack China that includes Taiwan interests and nothing happens), they also need to tell their majority how shitty and stupid Chinese are with the false or not, important to note or not, "it missed by 24 miles". They always have done things this way. Sometimes it's more truthful and honest like mentioning J-20 doesn't have intended engines at the start of service (but entirely ignoring the fact that J-20's T:W is pretty much as good as top 4th gen fighters even with AL-31 and WS-10).

For now, Chinese team running that test may not even have had the intention to test hitting accuracy and the intended guidance system wasn't even on board, with only a rudimentary placeholder and it could simply have been a test of concept for the flight itself and very general placeholder guidance to ensure it lands somewhere inside a designated range.

If it was a test of a totally finished weapon, they could simply have put a huge target somewhere as a deception so no CEP can be figured out by foreign intellligence. They could have informed of the flight and intended targeted landing site but with the landing site particulars as a total point of deception. There are literally multiple combinations and permutations of reasons and/or efforts and deception for just FT to "guess" at 24 miles out of range.

We know Chinese MaRV (with simpler trajetories but much fast speeds than HGV) used on ASBM (unique in the world still) with multiple sensor nodes, have pinpoint accuracy against moving ship targets. While HGV trajectory and flight pattern is much more difficult to control with perfect CEP, I'm sure this has long been achieved if MaRV accomplishing near pin point accuracy has been done and mastered since early 2010s.

Is there any good resource on Hypersonic cruise missiles by China? Looks like US might be fielding theirs Ina few years.

gongolongo said:

Is there any good resource on Hypersonic cruise missiles by China? Looks like US might be fielding theirs Ina few years.

Click to expand...

For cruise missiles (shorter ranged) there is only DF-100 that's been leaked to be in service and the H-6 carried air launched missile.

I guess these two types are sort of the known with photos and officially leaked types of ARRW/ HAWC and Zircon attack range equivalents. I would hazard a guess and say China's hypersonic weapons development is greater and deeper than what is shown since we only know about the ones that China and US officially have reported on and they don't report or know all of them. For starters, China has hypersonic wind tunnels with no equivalents outside of China. The JF-22 tunnel (or whatever it's called) is about the size of a hydroelectric plant and uses some serious chemical explosives as part of its function. The only kind in the world at this size, speed, and power requirement.

China also has so many world leading supercomputing facilities with some of the best supercomputers. It's also a global leader in academic research in AI and practical development and use of narrow AI.

As much as I think missiles like DF-ZF (DF-17), the mysterious H-6 air launched ballistic missile which surely carries an HGV due to there being simply no point for such a large booster air launched MaRV, and DF-100 are all more short to intermediate ranged hypersonic weapons (ballistic missile range definitions), the Chinese equivalent to HAWC and Zircon has not been leaked publicly yet but due to its short range and usefulness against ships, I would suggest that such a weapon is certainly in development and testing if not in service. Something like that is arguably a little simpler for China than it is for the US and Russia.

Hypersonic propulsion China is one of, if not the leader in. China readily leaks new tests and test flights of exotic hypersonic propulsion vehicles, even one it recently flown and landed (reusable craft). Leaks news about new breakthroughs in sodramjets and combined cycle engines. China has been testing scramjets for hypersonic weapons and craft for at least a decade with news of breakthroughs every few years. Again all those wind tunnels, supercomputers and armies of engineers are a helpful boost.

Even Xiamen university did a novel glide vehicle test for some academic studies into dual shockwave glide hypersonic flights. This is a second rate (in China), non-defence affiliated university and they are doing world leading experiments in hypersonic flight (note that a leading Australian engineering university also have done HGV experimental flights with US DARPA). The top dogs in Tsinghua, Harbin, Beida, Zhejiang, and the numerous defence universities and CAS! are playing with much more exotic stuff by that point already (years and years ago).

Combined cycle engines, again same breakthroughs after breakthroughs, tests after tests. To think PLA wouldn't have demanded a short ranged (ballistic missile range definition) scramjet or otherwise powered hypersonic missile for antishipping mostly? Something like that is simply too easy at this point.

Lets also not forget China leads in guidance, targeting, and communications technologies, not a centimeter behind the US at all. I have yet to see the US be able to use supersonic near space drones or satellites perform live microsecond accurate navigation and targeting for mach 10+ MaRV onto small moving ships from a missile launched 5000km away. And yet China's done these things with ASBM since 2010s.

ougoah said:

For starters, China has hypersonic wind tunnels with no equivalents outside of China. The JF-22 tunnel (or whatever it's called) is about the size of a hydroelectric plant and uses some serious chemical explosives as part of its function. The only kind in the world at this size, speed, and power requirement.

China also has so many world leading supercomputing facilities with some of the best supercomputers. It's also a global leader in academic research in AI and practical development and use of narrow AI.

Click to expand...

Just to add, the aerospace industry do not fully understand how wings generate lift

We understand some of it, but there is still a big unknown which makes aerodynamics something of a black art

Hence the importance of wind tunnels to obtain real-world results for given designs

No One Can Explain Why Planes Stay in the Air
scientificamerican.com/article/no-one-can-explain-why-planes-stay-in-the-air/

Click to expand...

AndrewS said:

Just to add, the aerospace industry do not fully understand how wings generate lift

Click to expand...

Its easy. Wings generate lift through anti-gravity.

The Drive states the chinese gov claims the flight was of a spaceplane, not a FOBS. The link Rogoway et al put in is to a chinese website that now gives an error. The Drive doesn't believe the Chinese (if the press conference took place) about the test being of a space plane rather than a FOBS.

anzha said:

The Drive states the chinese gov claims the flight was of a spaceplane, not a FOBS. The link Rogoway et al put in is to a chinese website that now gives an error. The Drive doesn't believe the Chinese (if the press conference took place) about the test being of a space plane rather than a FOBS.

Please, Log in or Register to view URLs content!

Click to expand...

Well, I guess you can call a HGV a "space plane (that glides at hypersonic speed.)"

It is hard to solve fluid dynamics problems in conditions of high turbulence. Especially so when you are dealing with plasmas and the like.
The models typically used to solve these problems are approximations and fail in such conditions. You can use huge computational resources to compute an approximation which handles these kinds of situations better but it is not 100% accurate either. Just more accurate the more time you spend on it.

That is one of the reasons why it has taken so long for scientists and engineers to develop either hypersonic flight or supercavitating torpedos. Development of hypersonic flight has been pursued at least since the 1950s and things like ramjets predate WW2 even.

Another reason has been limitations on available materials.

AndrewS said:

Just to add, the aerospace industry do not fully understand how wings generate lift

We understand some of it, but there is still a big unknown which makes aerodynamics something of a black art

Hence the importance of wind tunnels to obtain real-world results for given designs

Click to expand...

This also isn't a fair way to look at these things. It's like saying at a certain point, we don't know why the brain or cells etc behave the way they do.

With wings (and fluid dynamics) we don't know the full nature of turbulence. This doesn't mean we don't fully understand how wings generate lift. In fact we do know more than enough about it. We don't know how gravity works either but we know enough about it to accurately put satellites into orbit and so on. Just like we know more than enough about lift/buoyancy to design wings and ships.

At the most basic (and useful) level, lift is so simple I could explain and teach it to a high school physics student. Including airfoil angle of attack and the basic concept of how mechanical stability works. This isn't enough to design wings but I think it's highly unfair and inaccurate to say we don't fully understand how wings generate lift. In fact we know the useful, measurable, verifiable stuff and pretty much the entire puzzle piece except for the full explanation of turbulence and its behaviour is pretty much impossible to predict. It's more a pure maths and physics problem than an engineering one. For engineers, we care about experimentation and what can be repeated verified and used/exploited and for things to work and behave as expected, leave the full understanding to the purists.

As with plenty of new inventions and discoveries, they are developed and commercialised often well before the full depth of its physics is properly understood. For example, wings. As with plenty of these things, acceptance comes before understanding e.g. teaching high school kids calculus without explaining the fundamentals at all. Turbulence is just too complex and to be honest we sort of know the problem. It just reaches a level of complexity that is too damn high for now. Kinda like nth degree polynomials. I mean I think we reach around 4 before just going okay it's too complex for a formula. Numeric methods to solve problems involving high complexity. This is where supercomputers are extremely valuable.

I'm guessing aerospace engineers do not sit around pondering why it is that turbulence behaves in such and such ways and then figure out the full set of hows. They run 1000 wind tunnel tests and use various supercomputers to do their work. What you're talking about is a totally different thing to designing and "understanding" wings.