Published:
Mar 25, 2023 19:59 GMT
When activated, it would cause US sonars to mistake the sub for water.
Chinese military scientists have developed a new device that could help submarines neutralize enemy sonar. The apparatus is similar to a brick or mosaic and is based on Giant Magnetostrictive Material (GMM) technology. The mechanism is made of expensive rare earth elements whose reserves are mainly concentrated in China., according to South China Morning Post (SCMP).
This small active acoustic stealth tile can be glued all over the ship’s hull to deal with sonar beams from different directions. It can analyze the frequency of enemy sonar and emit high-intensity, low-frequency sound waves (up to 147 decibels) that can render the powerful and advanced sonar technology of the US Army or its allies inoperative. , well they would mistake the submarine for water.
According to SCMP, the paper’s authors wrote in their paper: “The underwater surface coating, widely used by the world’s naval powers, is anechoic mosaic.” However, these “passive” sound-absorbing devices, made of rubber or synthetic polymer, may not be as effective with long wavelengths, low frequenciesused by modern active sonars.
Based on this, the passive coating “can no longer meet the combat requirements of a silent submarine, no matter how the material composition and structure of the tiles change,” the scientists wrote.
For its part, the “active” mosaic is based on the phenomenon of magnetostriction, discovered in the 19th century by the physicist James Joule, which consists of the change in size of materials when placed near a magnet. Terfenol-D, created in the second half of the last century, was the first MMG with which it was possible to generate visible changes in its shape. when faced with a magnetic field. Today it is in wide use in active sonars on many US warships.
rare earths
However, since the manufacture of GMMs requires a large amount of rare earth elements such as terbium and dysprosium, the reserves of which are mainly concentrated in China, the application of this technology remains limited. This is China’s strategic advantage.
The researchers packaged all the components in a small format while maintaining high power output for rapid installation on submarines, as well as proper long-term operation and maintenance in deep oceans. “The delivery unit is lightweight, operable in a wide range of frequencies with high efficiency and resistant to pressure.the authors wrote in their post.
