Bullet cavitation

[nickshawn11]

Sorry this is not entirely cavitation. For the most part, the viscous forces are merely overcoming the inertial forces (see Reynolds number), creating a cavity behind the bullet/sphere. Actual cavitation is probably occurring in a small ring on the back surface of the bullet. I suggest trying a different approach to observe the effects of cavitation..essentially you're going to want to avoid any chance of aeration..

[rickypigazzini]

@nickshawn11 You're right, see my reply to antony1103, i explained where the bullet is actually cavitating and where is ventilating.

[nickshawn11]

@rickypigazzini perhaps you still miss understand, the 'true' cavitation would consist only of water vapor (assuming the projectile is entering water). The large bubble behind the bullet mostly consists of air and will not self collapse after the pressure differentials are equalized...The reason why I say the bubble mostly consist of air is because at 0.02 we can both agree this is air, you will also notice this air does not escape..

[antony1103]

not cavitation either

[rickypigazzini]

@antony1103 Until 0:02 (spash) you could think that this is only a ventilation, because the bubble is not closed and connected to the surface, but as you can see at 0:05, the bullett is "carrying" a relative steady bubble, and this is cavitation.This because the pressure differential is kept over the cavitation limit altough the body is submerged. Such a large cavitation bubble behind a relative small body is often called "supercavitation". see my video "supercavitation" and "bullet in water"

[antony1103]

@rickypigazzini can this even be considered cavitation at all.  I think nickshawn11 explains it well talking about the vapor pressures. Assuming the gel is a mixture of long chain hydrocarbons (i could be wrong), I don't think the pressure drop is sustained for a long enough time to unwind the matrix and create a "gas". I've just finished some studies on cavitation, but really didn't get a chance to research anything but water mixtures.

[vapourmile]

You get a similar effect playing level one of Konami's Salamander.

[Derail07]

not a bullet

[wrxbungle]

@Derail07 actually, it's not even a video, either. this isn't even youtube.

[mrfuzzyibrows]

hadouken!!!

[STINKFISHcompany]

awesome, that was exactly what i was looking for :D

[FireplayerStas]

nice