Chinese reportedly working on submarine that would ‘fly’ in an ‘air bubble’

 

A supercavitating submarine creates a bubble of air that encompasses the whole vehicle by ejecting gas through the nose with enough force that it forms water vapor. This greatly reduces drag and allows it to travel at high speeds not possible by standard submarines. (Sources: Defense Update, Popular Science, South China Morning Post. Graphic: Tobey – The Washington Post)

In the annals of vehicular locomotion, the submarine is the equivalent of the Walkman. It dazzled the masses when it hit, flexing nuclear-tipped missiles that completed the “nuclear triad” of deterrence.

But other technologies soon surpassed it in terms of speed and agility. Now, years later, the submarine may be making a comeback — at least theoretically. Researchers at the Harbin Institute of Technology in northeast China tell the South China Morning Post that they’re hard at work on a submarine that the newspaper claims could travel the 6,100 miles from “Shanghai to San Francisco in 100 minutes.”

That’s not in the cards. But there’s plenty of reason to believe a submarine could be built that would significantly exceed the speed of today’s fastest models, which lumber along at a speed of 40 knots (about 46 mph.) It all has to do with friction and how to conquer it.

The reported plans for the super-fast Chinese submarine draw on research that reaches back to the Cold War on “supercavitation,” a technology that creates a friction-less air “bubble” around a vessel that allows it to “fly” underwater, facilitating incredible speeds. The Russians have developed torpedoes that travel faster than 230 mph using that approach.

Now researchers at Harbin’s Complex Flow and Heat Transfer Lab are reportedly figuring out how to use that science to build submarines.  “We are very excited by its potential,” lead researcher Li Fengchen, a professor of fluid machinery and engineering, told the South China Morning Post. “… Our method is different from any other approach, such as vector propulsion,” which involves engine thrust. Rather, he would lubricate the vessel in a special liquid that would reduce water friction until the vessel would reach speeds high enough to enable “supercavitation.”