300knt torpedo

The following was sent as a post in a discussion list in a forum totally unrelated to boats but exchanging ideas about surface friction to flow of air/gas/fluid.
I found it intersting!

Have you guys heard of that russian torpedeo that goes 300 mph underwater? Shkval

The most interesting part of the 'affaire' Pope was what the American businessman was after: plans for Russia's remarkable 'Squall' torpedo. This weapon, 533mm in diameter by 8.23 meters long, has a reported underwater speed in excess of 200 knots (220mph), a range of 20 miles, and an operational depth of 400 meters. Naval sources say 'Squall' may even be able to travel at 300mph (500 kph) underwater.

'Squall' attains its unprecedented speed by making use of 'super-cavitation,' a hydro-dynamic principal known since Isaac Newton's day, but still only partially understood by western scientists. The missile is discharged from a sub's torpedo tubes by compressed air, then uses propellers until well clear of the sub. Or, it may be catapulted out. Then, a rocket motor fires, propelling the weapon to high speed. The 'Squall's' flattened nose streams water backwards and away from the missile's body, causing a large air bubble to form around the torpedo, which is maintained by high-pressure air pumped from the torpedo's nose.

Conventional torpedoes travel at 35-45 knots; the fastest western weapon, Britain's 'Spearfish,' hits 75 knots. All struggle against water resistance. By contrast, the air bubble from super-cavitation that envelops 'Squall' almost totally eliminates friction with water, permitting enormous speed. The only part of 'Squall' that actually touches water is its nose.

 

Not being especially knowlegeable about hydrodynamics, I'm hesitant to get too deep in this. However, this sounds too much like an urban legend to me.

The torpedo may not have much wetted surface and resultant water friction in this scheme but, there is still the passage of the air bubble through the water. Ever watch an air bubble rise through water? If there were no resultant friction, it would rise infinitely fast. We know it rises pretty slowly so there must be a lot of resistance to its motion. The water still has to get out of the way and come back to its normal state.

If the thing is capable of operating at a depth of 400 meters and maintaining that air bubble, the internal air source must overcome the water pressure of over 500 PSI, if I multiplied correctly. Where does it get all this air? Who thought this one up?

Ok, I stuck my neck out. Anyone want to swing the ax:?:

 

http://www.periscope.ucg.com/mdb-smpl/weapons/minetorp/torpedo/w0004768.shtml
http://www.newsmax.com/archives/articles/2001/4/23/220813.shtml
http://diodon349.com/Kursk-Memorial/Warpdrive_underwater.htm

This doesn't sound like an urban myth to me!

 

More info on high speed torpedoes, supersonic submarines and the like:
http://www.globalsecurity.org/military/world/russia/shkval.htm
http://www.onr.navy.mil/sci_tech/engineering/333_mechanics/usea_highspeed.asp
http://www.subsim.com/ssr/page33.html

Taken from the Fatima Network:

"The Kursk which sank in 354 feet of water in the Barents Sea on August 12 with 118 on board, was an Oscar II-type nuclear cruise missile submarine — the leading submarine participating in the largest naval exercise the Russian North Fleet had staged in a decade.

The vessel, according to the London-based Soviet Analyst, was engaged in the mock sinking of US submarines and aircraft carriers, and was under observation by two US submarines located some 50 miles from the scene, together with several other allied monitoring vessels.

The Kursk was also testing a new weapons system, a superfast torpedo that travels at speeds of over 230 mph...."

 

In one of the links I listed above there is a claim that a high Chinese naval officer was in the Kursk to observe tests of the latest version of the Skhval, of which the Chinese were interested in buying. Other claims say that the Chinese are already in posession of those underwater rockets for the defense of the Taiwan to mainland straits.

As interesting as this scientific claim sounds the amount of energy it will require to propell such a thing limits it to military use and therefore we may never get to ride in one

Not that I think that I would want to travel at that speed underwater when it is already a headache sailing at 7 knots with a 6' draft!

 

Well, the way I understood it is that there is no air involved but vacuum of displaced water, just as the air is displaced by supersonic jets.
My question would be more on the tail of the beast, if there is such a pocket created for it to slide in, what's behind it and therefore how can it get propelled efficiently even with jets!

 

only an hour ago i was checking the new jane's, 300 knots the thing does.
some years back i came across us navy sites bidding big money for similar or better speeds.

 

Hey Zero, it was your first post that said the torpedo injected high pressure air from its nose. That is partly (only partly) what confused me. I'm glad I said that I'm no expert at such things since the torpedo is claimed to exist by so many others.

The lack of anything behind the torpedo would not reduce thrust of the rocket motor at all. Might even increase it. The massive thrust required by such a weapon at the speeds given still blows my mind. I also wonder how they keep the collapsing vacuum from tearing up the aft part of the torpedo? Cavitation in propellers, which is the same thing, are prone to tear up the metal. High speed super cavitating propellers have a very blunt trailing edge so the vacuum bubbles collapse away from the blade.

 

A possible explanation it that it doesn't mind as the life of the torpedo is only of a few seconds or minutes at the most.

 

Interesting topic especially when coupled with the quote:
"People demand freedom of speech to make up for the freedom of thought which they avoid."
Soren Aabye Kierkegaard (1813-1855)

I wonder if it is possible to use thought to reverse engineer this high speed hydro-rocket. I would power it with hydrogen peroxide passing through a silver catalyst. The slight mushroom shaped nose would have nozzle apertures around the under side of the mushroom cap. This would create a plume of superheated steam which would drive out the gases that are dissolved in the water creating a massive directional flow of bubbles, initially and substantially reducing the wetted surface area and friction.

Once the rocket gets up to speed the cavitation starts, especially in the lee of the mushroom nose cone.When the torpedo gas envelope passes the location of the torpedo itself, there is probably going to be sonoluminescence as the bubble implodes at hypersonic speed. This would indicate a substantial audio signature which could be tracked. But at that speed what vessel could hope to get out of the way?

 

What if you fire this torpedo oh, lets say 2 miles to target at 2 or 3 hundred mph ,you hit a piece of seaweed or a something? would that be like jumping off a cliff or bridge into a river and have the cement factor? and as far as the technolidy goes they cant even keep thier boats floating, (but never under estimate your enemy) as far as American buissinessman go ,they may be the straggelers.the real buisinessman are in the CIA maybe we have a torpedo that goes 600mph ?

 

OK, the 600 MPH torpedo is a very long needle shape and it is made of ice that has been frozen at liquid helium temperatures (this reduces the meltdown speed). It sheds water as it goes so it never really has any friction. It is sized to have the ice be melted at the proper rate so that only the payload is there at the end. It only has frontal area and the requirement to part the water that it flows through. The hydrogen peroxide will work as a fuel but it must have the nozzle at the rear so that it does not heat the ice.

 

600mph torpedo and unmanned nuke sub......mmmm ......... I better leave earth?

 

There is a nice description of the missile on this web site
http://www.marinetalk.com/articles_HTML/xxx00092653TU.html

And a pic of its vital parts. As far as I've read this is the version 1 and there is a 3rd generation missile of its type with sophisticated guidance systems.

I totaly misunderstood the principle at the begining but the more I read the more flubergusted I get! So the significance is not at propulsion but at the gas bubble generated. Unbelievable!

I'd call it the sneezing dolphin!

 

I'm afraid I take all this with a pinch (well a bucket full actually) of salt! As some of us may remember during the cold war we were given allsorts of stories as how fantastic the Soviet Union was and had millions of super trained soldiers just waiting to pounce (few could understand why they didn't!) following peristroka or whatever it's called it was discovered that the one thing the Soviets were good at were fairy stories - a lot of these fantastic stories were just that! Stories! Whilst I wouldn't discount the possibility of Russia (guess who the former Soviets have turned into) having some extremely fast torpedoes which may have a degree of accuracy is it possible to prove they are that good? From what I've seen of the Russians I doubt it! I've found from life that if a country has a high standard of living then their secret equipment tends to be good! If the other way round (Eqypts shiny airplanes in the bitter lakes (1960's) comes to mind, looked good but turned out to be cardboard and kitchen foil! Had us guessing for a while!). Look at the US of A for example, you guys have a good standard of living - lots a cars televisions and all that rubbish AND your Military Equipment tends to be good to excellent (this is about the mechanics of the job not the ability to use it! ) fer instance!

Just a thought!