supercavitation torpedoes

hello people!
I am new around and mostly just reading...
Anyway have you heard about supercavitation torpedoes? What do you think about them?
The principle is to have a "bubble" of gas that surrounds the torpedo such that the friction is reduced by many orders of magnitude. The only problem that (at least) we had was the stability of the bubble. You basically have a big mechanical oscillator (spring-like) that has a natural frequency and you want to avoid resonance. There are a lot of interesting things going on there and most of them are workable... I was just wondering if you have more details about this.

I heard US military is also working on this sort of project.

MIG-29

Hi, Soyuz, and welcome to the site. I did some footwork for you and will post links to a few threads on ATS that discuss these torpedoes. Experiment with the ATS search features, boolean and integrated-Google, to dig up information that may already exist here. You'll be surprised what has been talked about.

Also, you may want to do some web searches on Shkval to get started. Here are the ATS Search results

...and IMO, a very good thread on the subject: New kind of torpedoes

[edit on 6-11-2004 by Spectre]

I remember reading about these types of torpedoes while studying about whales and dolphins. Below is a very similar article to the one I read before. They're not exactly the same, but it's close enough to get the point across IMO. The Point is that this technology may have some serious side-effects which are dangerous for the surrounding wild life. (ie: Whales, Dolphins, etc.) Like always, this isn't a concern of the Military War Pigs however, who's single purpose is to perfect their ability of Destroying Life.

According to a 22 July 2000 article in the New Scientist, by Duncan Graham-Rowe, "... It's loud, it's rocket powered and it's ... the supersonic sub ... Rather than being streamlined, a supercavitating object needs a flat nose ...


the body has to be going pretty fast--at least 180 kilometres an hour, or 50 metres per second ... Then, at high speeds, the fluid is forced to flow off the edge of the nose with such speed and at such an angle that it can't wrap around the surface of the body ... [so that the sub is in] ... a single bubble or supercavity ... A supercavitating body has extremely low drag, because its skin friction almost disappears. Instead of being encased in water, it is surrounded by the water vapour in the supercavity, which has much lower viscosity and density. ... in a supercavitating vehicle, only the nose of the craft causes significant drag, because this is the only part of the body actually in contact with the water. ... The overall drag reduces enormously once you reach the supercavitating regime ... and then increases only linearly with speed. ... the early 1990s ... the Russians ... produce[d a supercavity] ... torpedo .... Called Shkval, meaning squall, it is said to be capable of speeds as high as 500 kilometres an hour. ... the US Naval Undersea Warfare Center (NUWC), in Newport, Rhode Island. ... established its own supercavitation programme ... In 1997 ... NUWC researchers announced they had gone supersonic. An unpowered projectile, with a carefully designed flat nose and fired from an underwater gun, broke the sound barrier in water. That's nearly 5400 kilometres per hour--or 1.5 kilometres per second. ... Already they aren't very far off the 2.5 kilometre-per-second speed record for conventional munitions in air ... For ... supersonic underwater travel ... , probably only a nuclear reactor is a compact enough power source. ...".



"... Eight whales beached and died
soon after the U.S. Navy conducted anti-submarine exercises off the northern Bahamas,


... Navy Cmdr. Greg Smith said the sonar tests were scheduled only one day and took place from about 1 p.m. to 5 p.m. March 15 [2000] off Abaco Island. Marine biologist Ken Balcomb of the Earthwatch environmental group said beachings began that same day and within two days at least 14 whales had grounded themselves on Abaco, Grand Bahama to the north, and Eleuthera to the south. Eight died ... the Navy planned to continue such tests. ... Naomi Rose of the Washington-based Humane Society of the United States ... said ... "These signals, depending on frequency, could travel quite a distance and could even wrap around the island, ... One could argue that they [the whales] fled the area where the sonar was being transmitted.'' ... Balcomb said the mammals included several deep-water beaked whales, goose beaked whales measuring 16-19 feet, dense beaked whales measuring 10-13 feet, baleen whales measuring up to 27 feet and some small minke whales. Michael Breynan, director of the Bahamian Fisheries Department, said ``I am not aware of any similar incident (having occurred) in the Bahamas.'' ... [Navy Cmdr.] Smith said the exercise was testing for upgrades of what the Navy calls the Directional Command Activated Sonobuoy System. The exercise involved a Navy P-3 aircraft dropping two buoys north of Abaco, one as close as 35 miles to the island, the other 70 to 75 miles from the island. One buoy emitted a sonar signal which was received by the other, and a submarine was moving between the two buoys. He said the exercise had nothing to do with low frequency active sonar, a new and controversial system that transmits sonar pulses so loud they can match the roar of a rocket launch. ...", according to a 21 March 2000 AP article by Jessica Robertson.
www.innerx.net...

The office of naval research high speed undersea weapons project has three tasks: 1. supercavittation physics 2. vehicle guidance 3. vehicle control. Supercavitation phyics deals with the fundamental understanding of supercaviation, and numerical of two phase flows. Vehicle guidance deals with acoustic and non acoustic sensors, signal processing, waveform design, homing techniques ad the auto pilot and controller that are used to guide the weapon to its target.

globalsecurity.org

[edit on 16-11-2004 by blue cell]

The torpedo doesnt surround itself using a bubble of air, but water vapour.

Cavitation is the principle where in area's of water with very low pressures (think bernoulli's eqn) the water vapourises to create a bubble (or cavity hence the name). It is a form of low temperature boiling. The front tip of the torpedo is designed to form a large enough cavity for the rest of the torpedo to be in thereby reducing the frictional drag (torp is in vapour not water- hence a massive difference in density=> reduction in drag). This can normally only occur at speeds over 100knots (below that the full cavity wont form), hence the use of rockets on the russian design(remember-its in vapour not water so a prop wont work!).

Most of the past reseach has been to avoid cavitation, when the cavities meet areas of high pressure again they implode causing massive damage to metal surfaces such as propellers and rudders (it will eat through a metal prop in no time whatsoever if the prop isnt designed right!!! - have seen it, is v. funny).


Directional control of the cavity is extreamly difficult hence the russian torp only being able to travel in a straight line. It is however being worked upon by a number of countries invluding russia, US, UK, Farnce and India (probably china too, but not sure).

The US has conducted reseach into supercavitating projectiles for use as mine clearance (from a heicopter) and self defense systems for submarines. None are known to be in service yet.

The ultimate aim is to produce small quick subs with the speed and agility of jetfighters but underwater. This scenario has been used to devlop a sci-fi/future tech film at www.deepangel.com... This site also has some links to further information of supercavitation. (and yes i know it is fiction, but gives a good idea of what the tech's are working on).

As it says on the site run silent, run deep is history the fuure is to run fast run deep!!!

[edit on 13-11-2004 by paperplane_uk]

[edit on 13-11-2004 by paperplane_uk]