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?docid=-286940563133612507&q=ejected+from+boat&total=8&start=0&num=10&so=0&type=search&plindex=0

[RANCHI OTTO]

Thanks a lot...nice video!:p

[yipster]

bigger more stable boat would have been nice too :D

[RANCHI OTTO]

ASD....ASD....ASD....by OR:D

[babakshabani]

:p :) :p

[RatliffFranklin]

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]

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
http://www.navatekltd.com/images/midfoil1.jpg
http://www.navatekltd.com/images/midfoil2.jpg

[RatliffFranklin]

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
http://www.navatekltd.com/images/midfoil1.jpg
http://www.navatekltd.com/images/midfoil2.jpg

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/2006/04/iran-and-nuclear-weaponry-i.html
http://www.defensetech.org/images/shkval_drawing.jpg

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/wikipedia/commons/a/a8/Shkval.jpg
http://upload.wikimedia.org/wikipedia/commons/f/ff/Shkval_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/
http://i184.photobucket.com/albums/x295/kach22i/Wild-Concept-1.jpg

[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]

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.

[kach22i]

Another twist:
Imagine that the upper aerodynamic part detaches and flies away on it's own.

Imagine the submerged pod is not rocket powered, but something more conventional.

Is what we have now considered an aircraft carrier?

Is it a "Flying Sub"?

Maybe it's just a boat and a dinghy.:D

[RatliffFranklin]

Another twist:
Imagine that the upper aerodynamic part detaches and flies away on it's own.

Imagine the submerged pod is not rocket powered, but something more conventional.

Is what we have now considered an aircraft carrier?

Is it a "Flying Sub"?

Maybe it's just a boat and a dinghy.:D

Since the surface pod would not be sustaining the stresses of a conventional hull, it would not need to have a structure as robust as a conventional boat so I suppose it could be designed to operate as an independent aircraft.

[zaltiy]

The supercavitating idea based on shkval torpedo working principles looks interesting at the beginning. However the major drawback even if you manage to fit your wetted surface into this air babble there are not a lot of things you can do with maneuvering as the babble is extremely sensitive to direction change. By the way the fins are used to pilot the torpedo with the aid of the gases. Supercavitation is already applied to hull forms i.e. supercavitating hulls and even special hulform designs are in the market that use air to reduce the wetted surface area of the hull with approximate 3% penalty on the engine's power (in order to generate and sustain the air babble).Thus without even discussing if this could be a cost effective solution, even if you do such a design it might be quite difficult to maneuver it, unless you want it to go only straight :)!

[RatliffFranklin]

The supercavitating idea based on shkval torpedo working principles looks interesting at the beginning. However the major drawback even if you manage to fit your wetted surface into this air babble there are not a lot of things you can do with maneuvering as the babble is extremely sensitive to direction change. By the way the fins are used to pilot the torpedo with the aid of the gases. Supercavitation is already applied to hull forms i.e. supercavitating hulls and even special hulform designs are in the market that use air to reduce the wetted surface area of the hull with approximate 3% penalty on the engine's power (in order to generate and sustain the air babble).Thus without even discussing if this could be a cost effective solution, even if you do such a design it might be quite difficult to maneuver it, unless you want it to go only straight :)!

I've seen a 300 mph boat in action. The predictability and consistency of a submerged supercavitating pod would be a huge improvement. Trust me on that one.

[kach22i]

I'm thinking that the vertical fins which hold the upper body to the submerged supercav pod could pivot. The fins would then be acting as rudders without need for other rudders on the pod below.

Also I've seen in thrust vectoring diagrams where increasing the thrust on one side tends to pull the rest of the thrust with it, and in turn results in thrust vectoring without baffles or fins or elevator plates.

[RatliffFranklin]

I'm thinking that the vertical fins which hold the upper body to the submerged supercav pod could pivot. The fins would then be acting as rudders without need for other rudders on the pod below.

Also I've seen in thrust vectoring diagrams where increasing the thrust on one side tends to pull the rest of the thrust with it, and in turn results in thrust vectoring without baffles or fins or elevator plates.

Either or both could be doable.

[kach22i]

http://www.darkroastedblend.com/2007/04/stealth-ships.html
http://farm1.static.flickr.com/169/472157867_ddcd00859b.jpg
(image credit: Popular Mechanics)

[yipster]

from here (http://www.boatdesign.net/forums/showthread.php?t=3202&highlight=for+yipster) i saved some pics before they went of the net and i went berserk, which may be a good qualifacition designingthis stuff :P

[kach22i]

I never knew there was a "very shallow water configuration" before.

Way cool.:)

[FranklinRatliff]

For covert ops why not just make a semi-submersible V-hull or tunnel hull? Submerge it for stealth then blow the ballast tanks when you need to haul ass.

[kach22i]

For covert ops why not just make a semi-submersible V-hull or tunnel hull? Submerge it for stealth then blow the ballast tanks when you need to haul ass.
It's been suggested/rumored that the Special Operation Forces (SOF) already has SOC of this type.

Similar to this:
http://www.globalsecurity.org/military/systems/ship/boats.htm
http://www.globalsecurity.org/military/systems/ship/images/SEALBOAT2.jpg
http://www.globalsecurity.org/military/systems/ship/images/SEALBOAT-1.jpg
http://www.globalsecurity.org/military/systems/ship/images/SEALBOAT3.jpg

Maybe not high-speed in the traditional sense, but high-speed in rough weather which is more important anyway.