Changes

A '''vortex''' (pl. ''vortices'') is a [[Rotation|spinning]], often [[Turbulence|turbulent]],  

A '''vortex''' (pl. ''vortices'') is a [[Rotation|spinning]], often [[Turbulence|turbulent]],  

flow of [[fluid]].  Any [[spiral]] motion with closed [[Streamlines, streaklines and pathlines|streamlines]] is vortex flow. The motion of the fluid swirling rapidly around a center is called a vortex. The speed and rate of [[rotation]] of the fluid are greatest at the center, and decrease progressively with distance from the center.

flow of [[fluid]].  Any [[spiral]] motion with closed [[Streamlines, streaklines and pathlines|streamlines]] is vortex flow. The motion of the fluid swirling rapidly around a center is called a vortex. The speed and rate of [[rotation]] of the fluid are greatest at the center, and decrease progressively with distance from the center.

<center>For lessons on the related [[topic]] of '''''[[Portals]]''''', follow [http://nordan.daynal.org/wiki/index.php?title=Category:Portal '''''this link'''''].</center>

<center>For lessons on the related [[topic]] of '''''[[Portals]]''''', follow [https://nordan.daynal.org/wiki/index.php?title=Category:Portal '''''this link'''''].</center>

== Properties ==

== Properties ==

Vortices display some special properties:

Vortices display some special properties: