Re: [Phys-L] vortex ring

[brian whatcott <betwys1@sbcglobal.net>]

This exchange struck me as an amusing instance of the human propensity 
for wanting to
explore model construction rules by confirmation, rather than by 
contradiction
as demonstrated here:
https://www.youtube.com/watch?v=vKA4w2O61Xo

1) Dye injection clearly shows the half ring structure of a vortex launched
 on a very smooth water surface.

2) Vortex rings are mathematically required to be continuous, so ignore 
this
half-ring example in favor of continuous vortex ring demos.

Brian Whatcott    Altus OK

On 12/4/2014 5:24 PM, John Denker wrote:
> On 12/04/2014 03:41 PM, LaMontagne, Bob wrote:
>
> > I thought the injection of dye into the water to see the vortex ring was pretty special
> Constructive counter-proposal:  Make or buy a vortex cannon
>     https://www.google.com/search?q=vortex+cannon
>
> and fill it with smoke.
>    https://www.google.com/search?q=vortex+cannon+smoke&tbm=isch
>    https://www.google.com/search?q=vortex+cannon+smoke&tbm=vid
>
> This strikes me as in every way easier and better than the
> so-called half-vortex in the water.