Scientists at the Harbin Institute of Technology announced a solution for problems related to "supercavitation", a technology developed by the Soviets that allows an object to reach the speed of sound underwater. The solution would be a special liquid membrane to reduce water drag.

Beijing (AsiaNews/Agencies) - Chinese scientists at the Harbin Institute of Technology's Complex Flow and Heat Transfer Lab have reached a breakthrough in 'supercavitation' technology. For Li Fengchen, professor of fluid machinery and engineering, his team' approach was ground-breaking.

Possible applications of the new technology include underwater travel to San Francisco from Shanghai in less than 100 minutes, a wetsuit that would make moving in the sea as light as flight, and a torpedo to destroy an aircraft carrier from the bottom of the ocean without giving its crew time to realise the threat.

The Soviet military developed the new technology during the cold war. It involves enveloping a submerged vessel inside an air bubble to avoid problems caused by water drag.

A Soviet supercavitation torpedo was able to reach a speed of 370km/h. hence, and in theory, a supercavitating vessel could reach the speed of sound underwater, or about 5,800km/h.

However, the technology has faced two major problems.

First, the submerged vessel must 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.

These problems can be solved, Prof Li said, through a special liquid membrane on the vessel's surface to reduce significantly the water drag.

After its speed reaches 75km/h or more the vessel would enter the supercavitation state, helping with steering and cruise control.

Few details have been disclosed and it will certainly take years before the technology became operational. However, China is not alone in the field.

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

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

• china
• supercavitation
• technology
• submarine