China a step closer to developing supersonic submarine

A world first, if the Chinese can perfect the 'supercavitation' technology.

---

Chinese scientists a step closer to developing supersonic submarine

The new ‘supercavitation’ methodology could see the vehicles travel at rates up to 3,600 mph underwater, being able to make the trip from Shanghai to San Francisco in about two hours.

BY DAVID HARDING
NEW YORK DAILY NEWS
Sunday, August 24, 2014, 1:54 PM



It is a distance of more than 6,100 miles.

But a team of Chinese scientists claim to have moved closer to developing a supersonic submarine, which could complete the journey from Shanghai to San Francisco in less than two hours.

Researchers from the Harbin Institute of Technology say they have developed a way to make a submarine — or torpedo — to travel at extremely fast speeds underwater.

Li Fengchen said his team of scientists can now create the complicated air "bubble" required for fast travel undersea.
This bubble gets rid of the drag created by water, which slows down travel.

A process called "supercavitation" allows a submerged vessel to travel inside an air bubble to overcome problems with drag.
In theory, it means the submarine could reach speeds of 3,600 mph, reports the South China Morning Post.

Li Fengchen says although this technology has been known about for some time, scientists have now developed a way of steering and overcoming the problem of a craft having to be launched at high speed by using a liquid membrane, which would control how fast the submarine would travel and direction.

"Our method is different from any other approach," he said.

it's similar to fart where a bubble of gas travels from the tummy to the rectum and out the anus passing through shit in the intestines. when it's pressurized, travels very fast and disintegrates your type 5 shit into types 6 and 7, it's called a run, and you have to run very fast to a shithole. :p

eatshitndie said:

it's similar to fart where a bubble of gas travels from the tummy to the rectum and out the anus passing through shit in the intestines. when it's pressurized, travels very fast and disintegrates your type 5 shit into types 6 and 7, it's called a run, and you have to run very fast to a shithole. :p

Click to expand...

Who'd have thought that shit could be an inspiration for sub technology?!

Despite some expected setbacks there is good reason to believe that soon China will be at the forefront of of R & D. Some Westerners still laugh at them but even right now China has surpassed almost every country in the area of finance and will soon do likewise in technology. To me there is no stopping the inexorable rise of this Chinese juggernaut. The Westerners should embrace this fact.

Supercavitation is not new. Its been proposed to improve submarine/torpedo performance as early as 1950s during the cold war period.

Cheers!

voucher said:

Despite some expected setbacks there is good reason to believe that soon China will be at the forefront of of R & D. Some Westerners still laugh at them but even right now China has surpassed almost every country in the area of finance and will soon do likewise in technology. To me there is no stopping the inexorable rise of this Chinese juggernaut. The Westerners should embrace this fact.

Click to expand...

The Chinese are too stupid to invent anything complicated. All they can do is copy.

Agoraphobic said:

Supercavitation is not new. Its been proposed to improve submarine/torpedo performance as early as 1950s during the cold war period.Cheers!

Click to expand...

Yes. But until now, supercavitation has only been used in torpedos fired at high speed in a straight line, not manned submersibles. Limitation is steering, inability to provide for turning at high speeds.

yellowarse said:

Yes. But until now, supercavitation has only been used in torpedos fired at high speed in a straight line, not manned submersibles. Limitation is steering, inability to provide for turning at high speeds.

Click to expand...

I dunno simi supercavitation.

but is it possible just mount a nuke warhead per torpedo or unmanned submersible and send multiple devices hurling across pacific toward USN bases on the west coast and also nuke west coast cities such as san diego which is a important USN/USMC city. what the cost compare to an ICBM?

sleaguepunter said:

but is it possible just mount a nuke warhead per torpedo or unmanned submersible and send multiple devices hurling across pacific toward USN bases on the west coast and also nuke west coast cities such as san diego which is a important USN/USMC city. what the cost compare to an ICBM?

Click to expand...

Sure, but you'd still need ICBM to target inland cities. Also, a supersonic sub has much more versatility than just as a launchpad for supersonic torpedos - manouevrability, drastically reduced travel time, intel gathering, evading enemy's sonar detection.

Supercavitation:

SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

BWAHHAHHAHHHHHA!!!!
Well not surprised at all, some people genuinely believe they were abducted by aliens.

http://www.scmp.com/news/china/article/1580226/shanghai-san-francisco-100-minutes-chinese-supersonic-submarine?page=all

Shanghai to San Francisco in 100 minutes by Chinese supersonic submarine
Chinese eye 'supercavitation' technology as future of underwater travel
PUBLISHED : Sunday, 24 August, 2014, 5:22am
UPDATED : Sunday, 24 August, 2014, 5:22am
Stephen Chen
[email protected]


China has moved a step closer to creating a supersonic submarine that could travel from Shanghai to San Francisco in less than two hours.

New technology developed by a team of scientists at Harbin Institute of Technology's Complex Flow and Heat Transfer Lab has made it easier for a submarine, or torpedo, to travel at extremely high speeds underwater.

Li Fengchen, professor of fluid machinery and engineering, said the team's innovative approach meant they could now create the complicated air "bubble" required for rapid underwater travel. "We are very excited by its potential," he said.

Water produces more friction, or drag, on an object than air, which means conventional submarines cannot travel as fast as an aircraft.

However, during the cold war, the Soviet military developed a technology called supercavitation, which involves enveloping a submerged vessel inside an air bubble to avoid problems caused by water drag.

A Soviet supercavitation torpedo called Shakval was able to reach a speed of 370km/h or more - much faster than any other conventional torpedoes.

In theory, a supercavitating vessel could reach the speed of sound underwater, or about 5,800km/h, which would reduce the journey time for a transatlantic underwater cruise to less than an hour, and for a transpacific journey to about 100 minutes, according to a report by California Institute of Technology in 2001.

However, supercavitation technology has faced two major problems. First, the submerged vessel has needed to be launched at high speeds, approaching 100km/h, to generate and maintain the air bubble.

Second, it is extremely difficult - if not impossible - to steer the vessel using conventional mechanisms, such as a rudder, which are inside the bubble without any direct contact with water.

As a result, its application has been limited to unmanned vessels, such as torpedoes, but nearly all of these torpedoes were fired in a straight line because they had limited ability to turn.

Li said the team of Chinese scientists had found an innovative means of addressing both problems.

Once in the water, the team's supercavitation vessel would constantly "shower" a special liquid membrane on its own surface. Although this membrane would be worn off by water, in the meantime it could significantly reduce the water drag on the vessel at low speed.

After its speed had reached 75km/h or more the vessel would enter the supercavitation state. The man-made liquid membrane on the vessel surface could help with steering because, with precise control, different levels of friction could be created on different parts of the vessel.

"Our method is different from any other approach, such as vector propulsion," or thrust created by an engine, Li said. "By combining liquid-membrane technology with supercavitation, we can significantly reduce the launch challenges and make cruising control easier."

However, Li said many problems still needed to be solved before supersonic submarine travel became feasible. Besides the control issue, a powerful underwater rocket engine still had to be developed to give the vessel a longer range. The effective range of the Russian supercavitation torpedoes, for example, was only between 11 km and 15 km.

Li said the supercavitation technology was not limited only to military use. In future, it could benefit civilian underwater transport, or water sports such as swimming.

"If a swimsuit can create and hold many tiny bubbles in water, it can significantly reduce the water drag; swimming in water could be as effortless as flying in the sky," he said.

Besides Russia, countries such as Germany, Iran and the United States have been developing vessels or weapons using supercavitation technology.

Professor Wang Guoyu, the head of the Fluid Mechanics Laboratory at Beijing Institute of Technology who is leading another state-funded research project on supercavitation, said the global research community had been troubled for decades by the lack of innovative ideas to address the huge scientific and engineering challenges.

"The size of the bubble is difficult to control, and the vessel is almost impossible to steer," he said. While cruising at high speed during supercavitation, a fin could be snapped off if it touched the water because of the liquid's far greater density.

Despite many scientists worldwide working on similar projects, the latest progress remains unclear because they are regarded as military secrets.

Wang, a member of the water armament committee of the China Society of Naval Architects and Marine Engineers, said even he had been kept in the dark about recent supercavitation developments in China.

"The primary drive still comes from the military, so most research projects are shrouded in secrecy," he said.

This article appeared in the South China Morning Post print edition as Shanghai to San Fran in 100 minutes by supersonic submarine

Re: SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

Dont hold your breath waiting for this. It will probably have countless screwups before they abandon the project.

Re: SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

ROLOLOLOL.......this is kinda facepalm.....so they want to turn water into air essentially,and make a submarine zoom thru water like its flying thru air.

Re: SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

Re: SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

Please send their entire nation in those vessels and send them to SF the soonest possible

Re: SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

In the near future Eatshitndie can chiong ktv at Huaihai Lu and make it home in time for dinner

Re: SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

Rogue Trader said:

In the near future Eatshitndie can chiong ktv at Huaihai Lu and make it home in time for dinner

Click to expand...

Don't think he's keen on a one way ticket :p:p:p

Re: SHOCKING NEWS FROM CHINA!!! Shanghai to San Francisco in 100mins...

How We Can Get Submarines to Travel at Supersonic Speed

• BY JORDAN GOLSON
• <time itemprop="datePublished" datetime="2014-08-27T14:15:49+00:00" style="box-sizing: border-box; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font: inherit; font-size: 12px; vertical-align: baseline; ">08.27.14</time>
• <time itemprop="datePublished" datetime="2014-08-27T14:15:49+00:00" style="box-sizing: border-box; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font: inherit; font-size: 12px; vertical-align: baseline; "></time>
• Axisymmetric ventilated supercavitation: ventilation increases and cavitation index decreases from top to bottom.
  
  Cavitation and Bubbly Flows Research Group , University of Minnesota

Chinese researchers say they are developing technology that would allowsubmarines to travel more than 750 mph. That’s faster than commercial aircraft fly, and yes, it is possible.

The technology is called supercavitation, and it’s been around for decades. The idea is to increase the speed of an object like, say, a submarine or torpedo by creating a bubble around it, reducing drag as it moves through the water. The nose of the vehicle typically is designed to create the bubble, and gas often is used to shape the bubble. The Soviets used this trick on the Shkval torpedo in the 1960s and ’70s; it was capable of 230 mph but for no more than a few miles.

Obviously, the concept is proven. But there are practical problems. “The devil is in the details,” says Dr. Roger Arndt, a University of Minnesota professor who works with the university’s terrifically named Cavitation and Bubbly Flows Research Group.

One of the stickiest wickets is steering a submerged craft that has little in the way of control surfaces in the water. A traditional submarine is controlled by a rudder, much like a conventional boat. Steering a supercavitating vessel requires having control planes pierce the bubble, producing great drag. These planes also would be under tremendous force and pressure at speed, and would need to be extraordinarily strong.

Another challenge: High speeds (for underwater travel) are required to maintain the bubble, perhaps around 45mph, though it would depend greatly on the size and design of the ship. It’s tricky just to reach a speed where a bubble can be created in the first place. So even if the Chinese researchers, at Harbin Institute of Technology’s Complex Flow and Heat Transfer Lab, have made a breakthrough in supercavitation, the limits of standard underwater propulsion will hold them back—especially if they want to make a real submarine. An underwater rocket capable of giving a supercavitating vessel long range doesn’t exist yet. Building a small torpedo is one thing, building a submarine capable of crossing the Pacific is quite another.


A wedge-shaped fin partially piercing a supercavity. Note the partial cavity forming from the leading edge of the fin.

Cavitation and Bubbly Flows Research Group , University of Minnesota

The Chinese researchers told the South China Morning Post they have developed a liquid membrane that tackles both issues. Continuously sprayed on, it would reduce drag and help get the vessel up to speed. The membrane could allow various amounts of friction to be applied to different sides of the ship, creating a steering effect. “By combining liquid-membrane technology with supercavitation, we can significantly reduce the launch challenges and make cruising control easier,” Professor Li Fengchen says.

Details on the new developments are scarce, however. “It’s a quantum leap to making a supersonic submarine,” says Arndt. “What they’re showing doesn’t give an inkling of what technology they’ve got.”

Whatever the Chinese team does have in pocket, it’s not the only one working on the idea of underwater supersonic travel. Arndt says Iran and Russia are among the many countries doing research, along with the American crew at the University of Minnesota. “Everybody is getting in on the act.”

So it may be a while before you clamber into a submarine for a quick trip to Shanghai, but the idea isn’t too far fetched, either.