Researchers at the Harbin Institute of Technology, China are attempting to create a supersonic submarine, which they envision would cruise through transatlantic underwater in not more than two hours.
Li Fengchen one of the lead researchers claimed that they are developing an air bubble that would assist in gliding at very high speeds underwater. One of the main problems with conventional submarines is the friction produced by water, which is far more than flying through air, and so the force renders the machine incapable of peddling at high speed.
During the cold war, the Soviet military did made an effort in creating an air bubble for transporting a submerged vessel. The technology was known as supercavitation. Although it helped solving the water-drag problem but only till some extent. Shakval, Soviet’s supercavitation torpedo was able to cruise with a speed of more than 370km/h, making it the fastest submarine amongst its contemporaries.
In one report, California Institute of Technology, 2001, had claimed of supercavitating vessel attaining 5,800km/h speed in underwater. Which if applied practically would mean, lessening the transpacific underwater journey to nearly 100 minutes and transatlantic journey to less than 60 minutes.
Limitations of supercavitating vessel
However, the supercavitation technology came along with two main huddles that were difficult to crossover. First, the launching speed of submerged vessel required to be around 100km/h. This velocity was important to create and sustain the air bubble. Second, steering the vessel with a rudder within the bubble was difficult to operate without any direct contact with water. Consequent upon which, the application was restricted to remote-controlled vessels only like torpedoes. Accordingly, it was applied to torpedoes that would only propel in forward direction without the ability to turn off-course.
Li claimed that his team has been able to bring about practical solutions to both the mentioned issues. Once the vessel is in water, it will consistently spew out liquid membrane on its surface. Although this film would fizzle out by water but in the intervening time, it would help in lessening the friction produced by water on the submarine at low speed.
Upon reaching 75km/h, the underwater ship would step into supercavitation state. The artificial film on the surface would assist in steering the various levels of friction that would be created across the vessel’s topography.
Liquid-membrane technology plus supercavitation
Merging liquid-membrane technology with supercavitation, the team was able to create a mechanism that was able to create thrust for its propulsion. Hence, reducing the launch challenges and tapping the cruising control. However, other equally important factors have to be considered before making the supersonic submarine travel a reality. In order to endow the vessel with a long-range ability, a robust underwater rocket engine is required to be developed. For reference, Russia’s supercavitation torpedoes could cover a range of 11km to 15 km.
As per Li’s envision, the supercavitation technology would not only find its application in military paraphernalia but it will also be used for water sports like swimming and civilian underwater transportation.
Superpowers aiming towards supercavitation technology
Germany, Iran and the United States along with Russia are also getting involved in creating supercavitation technology for applications including transportation and artillery.
Since more than a decade, the global research community had been working on supercavitation but the dearth of breakthrough ideas while resolving the complex scientific and engineering challenges were making it a daunting task. However, the current research looks promising and if everything goes well, we would witness travelling from Shanghai to San Francisco in just 100 minutes, now how cool would that be?
Source: South China Morning Post