High Speed Boat

[babakshabani]

Hello to all,

How do you think about the future form of high speed boat ?

do you have any idea?

[kach22i]

Robotic, because people are too delicate.

Video:
http://video.google.com/videoplay?do...arch&plindex=0

[RANCHI OTTO]

Thanks a lot...nice video!

[yipster]

bigger more stable boat would have been nice too

[RANCHI OTTO]

ASD....ASD....ASD....by OR

[babakshabani]

[RatliffFranklin]

Originally Posted by babakshabani

Hello to all,

How do you think about the future form of high speed boat ?

do you have any idea?

A hull that rides above the surface attached by struts to a submerged supercavitating pod.

[kach22i]

Originally Posted by RatliffFranklin

A hull that rides above the surface attached by struts to a submerged supercavitating pod.

Excellent suggestion, but let me ask or state a few things.

1. Does not a pod (or submerged sponson) lose it's buoyancy with air bubbles all around it?

2. Most Swath's for this reason are slow, right?

3. To get around this problem large (and thick) mid-foils which provide lift at speed and buoyancy at rest have been tried, see images below.

Mid-Foil by Navateck
http://www.navatekltd.com/midfoil.html

[RatliffFranklin]

Originally Posted by kach22i

Excellent suggestion, but let me ask or state a few things.

1. Does not a pod (or submerged sponson) lose it's buoyancy with air bubbles all around it?

2. Most Swath's for this reason are slow, right?

3. To get around this problem large (and thick) mid-foils which provide lift at speed and buoyancy at rest have been tried, see images below.

Mid-Foil by Navateck
http://www.navatekltd.com/midfoil.html

Supercavitating vehicles, such as the Shikval torpedo, aren't surrounded by bubbles. They're inside one big bubble. The Shikval has rear skids that ride on the surface of the water, except that water surface is underneath the ocean.

[kach22i]

http://actuajihad.blogspot.com/2006/...eaponry-i.html


http://en.wikipedia.org/wiki/Supercavitation

Supercavitation is the use of cavitation effects to create a large bubble of gas inside a liquid, allowing an object to travel at great speed through the liquid by being wholly enveloped by the bubble. The cavity (the bubble) reduces the drag on the object and this makes supercavitation an attractive technology; drag is normally about 1,000 times greater in water than in air.

VA-111 Shkval
http://en.wikipedia.org/wiki/VA-111_Shkval

The VA-111 Shkval (from Russian: шквал - squall ) torpedo and its descendants are supercavitating torpedoes developed by the Russian Navy. They are capable of speeds in excess of 200 knots (approximately 370 km/h).

http://upload.wikimedia.org/wikipedi.../a8/Shkval.jpg
http://upload.wikimedia.org/wikipedi...hkval_head.jpg

Questions:

1. How "perfect" or complete is the bubble?

2. Are the fins controlling direction, altitude and attitude?

[RatliffFranklin]

The Shikval has a speed of over 200 mph.

The swash plate nose is in contact with the water and deflected to provide pitch and directional control.

One theory of supercavitating flow predicts the bubble will collapse at around 400 mph. Another theory, based on hypersonic flows, predicts there is no upper limit.

[kach22i]

I'm going to get a little crazy on you for a moment, I trust you don't mind.

1. Even a super thin F-104 style vertical fin connecting the hull to the submerged pod will cause an explosion of water and a heck of a lot of spray.

2. Could the leading edges of the vertical supports also bleed out air?

3. This is the wild idea part; maybe magnalift support between the hull and pods? Some electro-magnets would be lifting, some pulling to maintain a constant distance.

4. Magnetic fields just to far fetched at this point in time, too Sci-Fi?

5. The Shikval is a kind of underwater hovercraft in my eyes, I like the concept. I've read about it for the first time only a few years ago. Perhaps in this forum.

http://s184.photobucket.com/albums/x295/kach22i/

[FranklinRatliff]

Good question. One theory of supercavitating flow, based on steam forming in the partial vacuum of the cavitation bubble, predicts the cavitation bubble will collapse at around 400 mph when the gas pressure can no longer sustain it. Another theory, based on hypersonic flows, predicts there is no upper limit since the bubble depends on the momentum of the diverted water not internal gas pressure. If the hypersonics based theory predominates, maybe no bleed out.

[tom28571]

George, One problem with your system is that, if it needs an above water vehicle, what is the need for the torpedo? Just use a missile in the first place.

Which brings up another point. What is the advantage of a fast torpedo over a sub launched anti-ship missile? Both leave a track that can be used to locate the launcher.

This is getting off the track of the thread, or maybe not.

[FranklinRatliff]

Originally Posted by tom28571

George, One problem with your system is that, if it needs an above water vehicle, what is the need for the torpedo? Just use a missile in the first place.

Which brings up another point. What is the advantage of a fast torpedo over a sub launched anti-ship missile? Both leave a track that can be used to locate the launcher.

This is getting off the track of the thread, or maybe not.

For a couple of things, riding on a supercavitating torpedo would give the boat ride height control you can't get with a missile. To get any real range, the boat would also require one of the waterbreathing propulsion systems that are now in the experimental stage.

The Russians developed Shikval so that whatever happened to the sub that fired it the target aircraft carrier would be gone in a mushroom cloud before anyone had time to think about countermeasures.