Vortex rings are endlessly fascinating, and they appear throughout nature from dolphins to volcanoes and from splashes to falling drops. One way to form them is to inject a jet into a stationary fluid. Viscosity between the fast-moving jet and the quiescent surrounding fluid slows down fluid at the jet’s edge. That slower fluid slips to the rear, only to get sucked into the faster -moving flow and pushed forward again.
The result is a spinning toroid, or ring. A similar method generates vortex rings by pushing a fluid out a round orifice. In this case, interaction between the fluid and the wall provides some of the force necessary to form the vortex ring.
A vortex ring is also formed in the left ventricle of the human heart during cardiac relaxation (diastole), as a jet of blood enters through the mitral valve. This phenomenon was initially observed in vitro and subsequently strengthened by analyses based on color Doppler mapping and MRI. Some recent studies have also confirmed the presence of a vortex ring during rapid filling phase of diastole and implied that the process of vortex ring formation can influence mitral annulus dynamics.
Video source:http://irvinelab.uchicago.edu/gallery.htm
Experiment:http://www.abc.net.au/science/surfingscientist/toroidalvortex.htm
Vortex ring - human heart:http://www.nature.com/articles/srep22021
Gif: A vortex ring produced by extruding fluid from a circular orifice imaged using bubbles.
The result is a spinning toroid, or ring. A similar method generates vortex rings by pushing a fluid out a round orifice. In this case, interaction between the fluid and the wall provides some of the force necessary to form the vortex ring.
A vortex ring is also formed in the left ventricle of the human heart during cardiac relaxation (diastole), as a jet of blood enters through the mitral valve. This phenomenon was initially observed in vitro and subsequently strengthened by analyses based on color Doppler mapping and MRI. Some recent studies have also confirmed the presence of a vortex ring during rapid filling phase of diastole and implied that the process of vortex ring formation can influence mitral annulus dynamics.
Video source:http://irvinelab.uchicago.edu/gallery.htm
Experiment:http://www.abc.net.au/science/surfingscientist/toroidalvortex.htm
Vortex ring - human heart:http://www.nature.com/articles/srep22021
Gif: A vortex ring produced by extruding fluid from a circular orifice imaged using bubbles.
No comments:
Post a Comment