On Wed, Apr 25, 2012 at 4:48 AM, William Beaty <bi...@eskimo.com> wrote: > On Tue, 24 Apr 2012, Terry Blanton wrote:
> It flies like a water-weenie toy: smoke ring propulsion. Ring vortices can > sometimes move without turbulence, since they are themselves a stable form > of turbulence (vortex shedding.) Reminds me of my fav toy in the 60's: http://www.skooldays.com/categories/toys/ty1114.htm > Speculating on shockwave-suppressed smoke-ring propulsion back in 2000: > > High-speed Vortex Blimp > http://amasci.com/amateur/vortgen.html#blimp Ah! I wonder if the inventor was inspired by that? > Question: inside a large sphere of fluid hanging in free-fall, if you launch > a travelling vortex-ring inside, will it be disrupted when it hits the > surface of the sphere? Or will pass through the interface and carry a blob > of fluid into the surrounding space? If the latter, then the large sphere > could be propelled by ejecting small spheres ...but wouldn't it only > experience a reaction force at the moment the small sphere left the main > mass, and not when the vortex-launcher was originally fired? Hmmm. Wouldn't it just suck air into the sphere? T
