That's gonna need either a very powerful and energy-efficient IEP system, or a nuclear propulsion system on those future destroyers.
Although, this could still be at least 2-3 decades away.
Chinese Hypersonic Developments (HGVs/HCMs)
- Thread starter A.Man
- Start date
Although, this could still be at least 2-3 decades away.
Wonder if you can do this type of “thermal” throat control using exhaust generated from a turbine instead.Xi Yazhou got a hold of his friend working in hypersonic field again to discuss the recent tests.
He says yes, even among people working in combined cycle engines who love to boast about every little achievement this test is considered extraordinary. Imagine how hard it is to get a scramjet working, then realize a working scramjet is only a very tiny part of this test.
According to TSTO, everybody is focusing a bit too much on the fact that this engine can transition seamlessly between four different modes. Indeed that is groundbreaking, but the jargon is disguising another never seen before breakthrough:
He says this part here, adjustable thermal throat is a decisive technological breakthrough and a key feature that allows this engine to function both as a ramjet and a scramjet. When the engine is working in scramjet or scramjet/rocket mode the air flow through the engine is supersonic the whole way through, in which case the engine can be thought of a just a simple straight tube. However during ramjet/rocket mode there is a problem: some part through the engine the flow is subsonic, and after the combustion chamber there is a need to convert this very hot but subsonic exhaust into cooler supersonic exhaust. This is normally done via a , the hourglass shaped looking thing you see at the bottom of rocket engines. In pure ramjet engine this is easy because you can just shape the engine into that shape and do it mechanically, however doing this in a combine cycle engine would case huge problems because in a combine cycle engine the nozzle will cause choked flow once the engine transition to scramjet mode.
An adjustable thermal throat gets around this problem by using small rocket engines on the inside of the combine cycle engine. The hot rocket exhaust is directed by the geometry of the engine so that the rocket exhaust itself forms an adjustable de Laval nozzle. This is what the "ramjet/rocket" mode actually means. When operating in this mode the rockets contribute very little thrust to the overall RBCC engine, rather they are mostly working as the nozzle for the ramjet.
TSTO also says RBCC engines designed this way, because they lack a physical de Laval nozzle can't actually work in a pure ramjet mode and the rocket will always have to be on to some capacity until scramjet kicks in. So although news report say there's a ramjet mode most likely what they mean is an where the rocket engines are firing and they serve mostly to heat and compress intake air which greatly improve the rocket's specific impulse and allows engine to produce thrust down to zero air speed unlike a normal ramjet.
During scramjet/rocket mode, mostly likely what's happening is the rocket is running in an oxidizer rich cycle which then produces rocket exhaust with a lot of oxidizer still left, this enriches the incoming air and allows scramjet to provide more thrust than it would otherwise be able to in flight regimes where scramjet is not normally optimized for.
He reckons the engine's modes are probably:
Mach 0-2: air-augmented rocket/ramjet mode
Mach 2-4: ramjet/rocket mode
Mach 4-6: scramjet mode
Mach 6-7: scramjet/rocket mode
Although the engine does switch between distinct modes at different speed, within a mode the engine will still need to finely monitor and adjust parameters, so that the boundary between different mode might be a bit fuzzy.
I tried to search up research paper on thermal throat and well what do you know, they're all about usage in scramjet/RBCC engine and written by Chinese researchers
@ashnole
Just another take on these statements on hypersonic weapons by the USAF
The cheapest hypersonic weapon looks like $46 Million for the Air Force ARRW.
The most expensive hypersonic weapon looks like $89/106 Million for the Long Range Hypersonic Weapon for the Army/Navy
20x cheaper would mean the Chinese equivalent missile would be in the range of $2-5 Million.
And my guess is that the equivalent missile is the DF-17 (ground-launched) or the DF-21 (with ground and air-launched variants)
EDIT
Why the huge disparity in costs?
If the Chinese military is procuring hypersonic weapons 5x faster, that will reduce development costs substantially.
At the same time, the Chinese military/government has built up a MIC over the decades with rocket fuel producers, missile design institutes and missile production factories who all compete with each other for contracts. And because there are so many contracts, the Chinese MIC can make large long-term investments to bring down the costs of missile research and missile production. I suspect there is a virtuous cycle going on, where lower-costs spur more development programmes and production, which then spurs further lower costs, and again more missiles.
It also helps that the Chinese MIC is cost-constrained because it is state-owned.
In comparison, in the USA, there is only a single rocket fuel producer. Previously there were separate private companies, but they merged, so now it is a single private monopoly that tries to charge as much as possible. And in terms of missile manufacturers, there are only 2/3? options in the USA, which amounts to an oligopoly.
But US ideology is vehemently against government intervention in the private sector, so I don't how they can fix this situation
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That statement would also be consistent with the 12 million RMB ($2 Million) figure for a DF-17 and the CSBA $20 Million figure for a 4000km IRBM like the DF-26.
“The main reason the countries are developing hypersonic weapons is for deterrent purposes. There is currently no defence against the weapons, so countries are building their own capabilities to deter a country like China or Russia. The reasoning is that a hypersonic missile strike by China or Russia could be met with a retaliatory strike by the defending the country,” Heath said.
What's with scmp only quoting western think tanks? Such bias from a Chinese writer. What's the point of jack ma even buying the SCMP and have it become another pro western mouth piece.
The article implies that the US and other countries want hypersonic missiles as a deterrent but purposefully omits the fact that china and Russia developed hypersonics as a deterrent to the US due to being surrounded by US bases.
antiterror13
Brigadier
$2M for DF-17 is extremely cheap, 1,000 unit is only tiny $2B.
If the USA sell weapon to Taiwan, China should sell this baby to Iran and Venezuela and Cuba and North Korea
I know. It sounds too good to be true.
But based on the USAF comments, if a DF-17 is $2-5 Million, it would still be a bargain.
also, materials is expensive. machining a custom part from common materials like aluminum or stainless steel often costs 100's-1000's USD. Doing it for an exotic material? 10000+. And that's for 1 material, for 1 part, for a rigorous materials screening process even at the end stage you're looking at multiple candidates for multiple parts.
AssassinsMace
Lieutenant General
All the US and the West can do is seed doubt and that only works if you control information in a country. Since they don't control China, and they do want to control information in China, it has minimal effect. I can remember when word that China started its hypersonic program, the usual suspects said well China doesn't have a glider, China doesn't have ramjet, scramjet, whatever... And now the US is even in more fear that they have to let public know about it as if the the American people had the power to stop it or they're trying to get them to pay for it for the US. A defense against hypersonic weapons...? That's about as realistic as those that say hypersonic weapons or engines to their potential aren't here anytime soon.
The reason the West is retreating in nearly everything is because everything they do cost more money than in China and they need a lot of it which they don't have. The more they say they care about the world, the more they have less control over it. The less money they make. The less resources they get. The less power they have. They had to spend a lot of money to get countries to favor them and not how they want to spin it that they're more naturally preferable. They simply just don't have the money because everything cost more for the West to do. The reason why the theme of the right of Western countries is going back to the good ole days means going back to a time where they did control everything. And that only came when they didn't care about anyone else meaning they don't care about human rights. They can't do that today because they're going to get nuked. You see it where they avoid the most actually sending their troops into Ukraine to fight Russia. And it's not even nukes they're worried most about. They don't want it costing them their lives by whatever means. So do you think they can go back to the days where they did control everything therefore it didn't cost them monetarily that much because they just took it?
They tried to claim there was a brain drain in China because people would rather live in the US than in China. Meaning they get paid more in the US. And that's one reason why everything costs more money in every step of economics in the West. China's Silicon Valley is filled with stories of Chinese who went back to China because the US wasn't so "friendly" to them meaning they faced the glass ceiling in the US or their economic opportunities weren't as great staying in the US. How about the prejudice of suspicion just for being Chinese...? And their fear of Chinese innovation and technology today shows everything they believed wasn't the case.
The reason the West is retreating in nearly everything is because everything they do cost more money than in China and they need a lot of it which they don't have. The more they say they care about the world, the more they have less control over it. The less money they make. The less resources they get. The less power they have. They had to spend a lot of money to get countries to favor them and not how they want to spin it that they're more naturally preferable. They simply just don't have the money because everything cost more for the West to do. The reason why the theme of the right of Western countries is going back to the good ole days means going back to a time where they did control everything. And that only came when they didn't care about anyone else meaning they don't care about human rights. They can't do that today because they're going to get nuked. You see it where they avoid the most actually sending their troops into Ukraine to fight Russia. And it's not even nukes they're worried most about. They don't want it costing them their lives by whatever means. So do you think they can go back to the days where they did control everything therefore it didn't cost them monetarily that much because they just took it?
They tried to claim there was a brain drain in China because people would rather live in the US than in China. Meaning they get paid more in the US. And that's one reason why everything costs more money in every step of economics in the West. China's Silicon Valley is filled with stories of Chinese who went back to China because the US wasn't so "friendly" to them meaning they faced the glass ceiling in the US or their economic opportunities weren't as great staying in the US. How about the prejudice of suspicion just for being Chinese...? And their fear of Chinese innovation and technology today shows everything they believed wasn't the case.
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