18 research outputs found
Evolution of the vorticity-area density during the formation of coherent structures in two-dimensional flows
It is shown: 1) that in two-dimensional, incompressible, viscous flows the
vorticity-area distribution evolves according to an advection-diffusion
equation with a negative, time dependent diffusion coefficient and 2) how to
use the vorticity-streamfunction relations, i.e., the so-called scatter-plots,
of the quasi-stationary coherent structures in order to quantify the
experimentally observed changes of the vorticity distribution moments leading
to the formation of these structures.Comment: LaTeX, 15 pp., 2 eps figures. Some sections have been rewritten;
referees' Comments have been include