Let's look at this convection from the side. This
image is a certain vertical cross section of the
fluid. Despite a temperature gap at both the upper
and lower boundaries, the distribution of temperature
forms a vertical stripe pattern. In
other words, there is very little change in
temperature vertically.
For better or worse the position of the vortices
is changing, so we can see in one instant many
different vertical cutoffs of a vortex. Looking at a
cutoff that grazes a rim of the vortex, we can see
that the vortex is rotating in
the reverse direction
top and bottom
like a cloth being squeezed out.
|