Re: [PSUBS-MAILIST] Bubble shapes!

[emm03@mirapoint.uow.edu.au]

>Actually , i have a question for those interested in physics 
under the water
>and mind games.
>he he lets see who guess it right here, Jeffrey you are 
welcome........
>what would be the shape of an air bubble in the water 
without the
>hydrodynamic effect (which deforms the bubble because of 
water flow)
>imagine an air bubble trapped in a container of water, 
itself going to the
>surface at the speed ascent of an  air bubble. so the only 
forces exerted on
>the bubble are the water pressure.   water around the bubble 
is moving with
>the bubble, so there is no flow around the bubble, the 
container takes the
>hydrodynamic forces.
>Herve




I think you have to take into two effects, the increasing 
pressure with depth (which is linear), and the internal 
spherically symmetrical gas pressure.
If we take an absurd example with a HUGE bubble, then the 
effects of the increasing pressure with depth is more 
apparent. The top of the bubble will become slightly 
distended towards the direction of lower pressure (i.e. the 
surface). The bottom of the bubble will be trying to 'escape' 
the direction of high pressure (i.e. the impenetrable 
depths..)
The result will be a slighly flat-bottomed, bell shaped 
bubble.
I have run some very quick and mostly nasty IDL simulations 
(about 10 lines of code) to prove my point, if you are 
interested in the result, then I can forward the images.
EM.