Propulsion systems for SuperSonic speeds movement underwater, how?

Ok, I was thinking about how slow submarines go, compared to Jet's, and I got to thinking, how could a device be made to allow submarines and torpedo's to go at SuperSonic speeds underwater.

Now, I don't know alot about hydrodynamics, so it's not something I've been able to figure out.


So, what kind of propulsion system could be created that would allow for a submarine and/or torpedo tp go at SuperSonic speeds?




MOD NOTE:
If tany mod/s think that there's a better place for this, please feel free to move it, this is just the best place I figured this should go.

The speed of sound underwater is five times that of air. The only way your going to get near that is with a rocket.

I realise how big a difference there is between moving in the air and the water, the drag etc.
That's more so anyone else who posts here does'nt think I'm totally devoid of knowledge.


I was'nt gonna state my theory, I realy wanted to see what other people thought of how to do this, but I think some sort of ElectroMagnetic manipulation could work.

It's called supercavitation.

A gaseous bubble is generated around the projectile, thus reducing water density and drag.


Here's a space theme;

www.supercavitation.com...

Thanks for the link Iskander.


Umm, if a mod want's to lock this, go ahead, not asking for it to be, just if any mod thinks it should be, I have no qualms.

The essence of submarine technology is stealth..keeping quiet and unseen/unknown. At least until it is to late and then it matters not that you are known.....also the ability to slip away ..after making yourself known...prively..quietly...back into the void.

The problem with these high speed systems is that they are not quiet. A rocket motor makes considerable noise. Underwater or in the air. While the simple fact of high speeds makes this somewhat irrelevant as the distances can be closed quickly..it can bode difficulty for the launching vehicle..if it is a submarine. Its location can be found quickly...especially if other submarines are pack hunting.

My point is that speed is not necessarily everything. The strategy is and always has been to be undetected..unitl it is desired for one to be detected..then to be able to slip away ..again ..undetected.

Any vessel moving rapidly through or underwater ..uses up alot of fuel..verses moving cautiously,quietly, and discreetly. Where are you going to store the fuel for all this high speed running??? Especially if it is rocket powered??? It is just not that practical.
While Im on it..does anyone know the range of these very fast rocket powered torpedos? I am thinking it is not a very long range.

Modern torpedos can be launched in a very quite mode...running slowly and quietly until it is time to close the gap..when they have come very close to thier targets..then the burst of speed to close the gap and .....Bang.!!!!
All this high speed stuff is just that ...high speed stuff. It is not everything. Some of you need to think further than the standard fear settings promoted in the media and group think.

One more very important thing to know about speed...underwater. This one you will not find mentioned in many articles on this race car, race track type mentality. High speed low drag.
There is in any underwater vessel or submarine..or weapon, a design limitation called the " Crush Depth" this is the calculated depth in which a certain design will implode..or crush under tremendous pressure of the depths.
Any vessel moving at great speeds underwater ..can reach crush depth very ....very...very ..quickly if someone at the wheel is careless..or even stupid....in just seconds....or less..depending on the speed. This applies to a weapon too. You'd better know what you are doing either in a weapon or a boat if you are going to try this kind of thing. You must have a fail safe method of controlling the depth at high speeds.
Think about how quickly one would go below crush depth at supersonic speed. This is very very serious buisness. Do not get all that enamoured of all this seemingly fantastic speed. It is not quite what it appears to be.


Thanks,
Orangetom

Any time!

Cheers mate.

Originally posted by iori_komei
Thanks for the link Iskander.


Umm, if a mod want's to lock this, go ahead, not asking for it to be, just if any mod thinks it should be, I have no qualms.

Supercavitation creates a "lubricating" effect, allowing the vessel to slip through the water.

The range of Shkval is over 7500 yards.

It's the future, it's here, it kiss a$$ and everybody is jumping on the bandwagon.

Cheers.

Yes but the difference between a supercav torp and a super cav sub is vast. In essence submarines are the long game chess pieces of modern warfare (using a standard chess metaphor your rooks bishops kings and queens if you will). The idea of a submarine is to move through covert means to an advantageous position then unleash a massive attack on multiple fronts.

To do this you need a maximally stealthy platform with a raptor like offensive weapon suite. At which point you sneak into range and launch blindingly fast strikes then slink back out to disputed territory and make another run inward at your opponents flankers and forward defenses.

A supercav sub is like a super heavy weight forward deployment cargo blimp... in other words redundant and dangerously suicidal.

astral_ice,

I'm not familiar with supercav subs, please let me know who makes/runs them.

To the best of my knowledge no one runs supercav subs... Although there are some supercav torpedo R and D programs. Mostly though the super cavitation concept is still very much a laboratory idea that hasn't been fully explored.

In the 90's Russia announced it had deployed the shkval, a supercav torpedo, it couldn't turn...but its top speed was 200 knots (230mph).

Russia is farther along in this tech then everyone else. The US has spent more time/money/effort on the stealth side, while Russia basically wants an underwater bullet, which method is better...who knows, but speed has always been an important part of battle.
It now seems that the US wants what Russia has...DARPA wants a supercav that can go 100 knots for 10 minutes while being controllable, the program is called Underwater Express.
Underwater Express Program

Heres a site that talks about some of the supercav torpedos.
Deep Angel

astral_ice. supercavitation effect has been identified in the early 20th century, and the Russian Shkval program goes back to late 70s, so your notion that "super cavitation concept is still very much a laboratory idea that hasn't been fully explored." is pure uninformed speculation.


Murcielago, DARPA indeed has began outlining the research program for supercavitating weapons, but Deep Angel is a computer game though. It is a good game from what I hear, but it has little relevance to this thread.

Supercavitation requires a somewhat rounded nose cone to produce the bubble or cavitation effect does it not??? I say this both in weapons or the weapons launching platform.
I say rounded verses the traditional pointed nose cones.
Does anyone know if this is true??
Does anyone know the approximate speed at which a bubble begins to form???


Thanks,
Orangetom

the most basic cavitator is a disc placed at the front of the nose of the projectile however any shape that causes a discontinuity in the flow enough to produce an area of low pressure behind the cavitator will work.

The speed at which the cavities form depends on a number of things, but are mostly related to pressure. The maths can get quite complex. If i get chance over the next few days i will sort some infomation out about it.

iskander please cite one article that says a manned or unmanned full size prototype designed to be manned has been tested before saying what I said is uninformed speculation.

I was very precise in my definition of manned supercav systems being at best laboratory or prototype systems.

Nothing anyone else posted contradicted me so do please tell what makes me uninformed in some way?

Wow Nice read and some very amazing stuff i discovered. I think you could get much more speed and stay stealthy with a hull design incorporating water pass thru's or water inlet outlets built in the hull design. Kind of like jet air in take cowlings. Less reistence in the water and Im sure less noise and at greater speeds. Just a thought.

astral_ice, your inability to properly formulate a sentence and comprehend its warranted response does not give you the right to insult me trough U2U. It is low and cowardly.

Your quote;

Although there are some supercav torpedo R and D programs. Mostly though the super cavitation concept is still very much a laboratory idea that hasn't been fully explored.

Your statement is incorrect, thus my reply;

supercavitation effect has been identified in the early 20th century, and the Russian Shkval program goes back to late 70s

I will address the issue to ATS staff.

Iskander, chill buddy.

Actually, there have been recent HUGE strides in magnetohydro propulsion. These 900 mph torpedos actually use magnetic manipulation of water to propell the item forward, very fast. Boats and subs will soon be propelled this way also. I think there was a post on ATS about water being made to flow uphill by scientists.

Basically, if you have a stream of water, and you have a magnet on the side of the stream, applying the right voltage will affect the stream of water. You can make it pile up, or you can make it dpress (accelerating the fluid). So somebody figured out that magnetized coils in the right series will provide constant, forward (or backward) motion.

Read about it here:

www.savoir-sans-frontieres.com...

[scroll down to English and select "The Silence Barrier"]

the problems with MHD for ship propulsion are well known. The principle one is that seawater does not connduct electricity well enough to generate enough force. This means that any ship propulsion system (were taking about MegaNewtons of thrust) are far too inefficient for use at present. We just cant yet make electromagnets strong enough even with superconducting materials.

The japanese tried about 15 years ago but only managed to get a speed of 3 knots