Can We Break the Underwater Barrier Like the Sound Barrier?

AI Thread Summary
The discussion explores the concept of breaking the sound barrier in water, comparing it to the phenomenon in air. When an object moves faster than sound in water, it generates a shock wave at its bow and experiences significant cavitation, where localized pressure drops cause air bubbles to form. This is exemplified by supercavitating torpedoes, which utilize a bubble of gas to reduce drag and achieve high speeds. The conversation clarifies that moving faster than sound in water is distinct from moving faster than water molecules, emphasizing that the speed of sound varies with the medium's density. Overall, while no conventional boats or torpedoes reach the speed of sound in water, supercavitating designs can effectively create conditions that allow for rapid underwater movement.
oozie1
[SOLVED] Underwater barrier

[?] Since I've been lookin a the concept and knowledge to what happens when the sound barrier gets broken and how it happens, it got me thinking about if the same thing can happen in water.
i.e. If an object was to move faster than the water molecues could move what would happen?
An if anything at all would it be physically possible.

----------OOZIE--------------------
 
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You would get a water shock wave forming at the bow of the object. Sonar wouldn't work (the sound would be going slower than the object).
You'd also get huge cavitation: localized drop in pressure would cause air to bubble out of the water (I don't know the technical term for the phenomena).

Do a search for 'supercavitating torpedos' for a real life example of this. Cool Stuff.
 
A couple of points: moving "faster than sound" means moving faster than a sound wave. It has nothing to do with "moving faster than water molecules".


The speed of sound increases as density of the medium increases so the speed of sound is greater in water than it is in air. At the same time, it is harder for a physical object to move through a denser medium. No boat or torpedo goes anywhere near the speed of sound. Propellors spinning rapidly can: that's where you get "super cavitation".
 
Actually, the supercavitating "torpedos" do move faster than sound in water, afaik.

They are shaped in such a way that a bubble of air cavitates around it, and it effectively turns into an underwater missile.

EDIT: You're right though, Ivy. Those "torpedos" (which are still in development) don't actually go faster than sound in water. They form a bubble of *not water* which they are going fast in.
 
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[?] thanks for that and to the person above the post above.
I saw that definition of speed of sound. an i thought that the sound barrier is when an object moves faster than air particles can move. I was just asking if a similar effect happened in water i wasnt saying they were related!
Thanks both
-----------------------------OOZIE-----------------------
 

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