What is the principle of supercavitating torpedo?

Supercavitation is a physical phenomenon. When the moving speed of an object in water exceeds 1.85km/h, a strange large steam ditch will be formed at the tail of the object, and the medium contacted by the object will change from water to air. Because the air density is only 1/800 of water, the resistance of the object can be greatly reduced, and large bubbles will be formed on the surface of the object. This is ". The first users of this principle are researchers from the former Soviet Union, whose underwater speed can reach more than three times that of traditional torpedoes. .

As early as 1970s, the former Soviet Navy developed the rocket-propelled "Blizzard" supercavitation "Storm" hypervelocity torpedo and "Storm" hypervelocity torpedo sailboat BA-III.

The speed reaches 370 km/h (about 200 knots), and its bubbles are generated by itself at ultra-high speed, and the tail gas of torpedo engine is led forward to release. It is also reported that the United States has also launched a comprehensive plan to develop supercavitating weapons; France has always been interested in supercavitation technology, bought several "blizzard" torpedoes from Russia for evaluation, and is implementing the "cavitation coordinated action" plan to conduct an experiment of airborne anti-mine supercavitation bombs; In cooperation with the research department of the US Navy, Germany has carried out a joint project of designing a new cavitation generator and modeling a torpedo homing system, and has also completed a supercavitating torpedo prototype, which will be tested soon. Russia's "Blizzard" rocket-powered torpedo is world-famous and is a known supercavitating weapon. After 10 years of secret research and development, the former Soviet navy was equipped with troops in 1997. The "Blizzard" torpedo was developed by the Ukrainian Institute of Fluid Mechanics. It is 8.23 meters long and weighs 2697 kilograms. Its shell tapers from the tail to the head, and the head is equipped with a warhead. At the center of the tail is a large-caliber solid rocket engine nozzle, surrounded by eight small cylindrical starting rockets, which accelerates the "snowstorm" to the supercavitation speed, and then the main engine starts to work. There is also a 1 guide wire shaft at the tail. When the torpedo runs in the water, the tail gas of the torpedo engine is led forward to release the release wire, which is used to control the movement of the torpedo and the initiation of the warhead.