The program used for the numerical simulations is named nsevol; you see its logo at the top of this page. Since it uses the Navier-Stokes equation to compute the evolution of a certain vorticity distribution, the program's name is to be pronounced as 'en-es-evol'.

The following subjects and examples are currently available

(with [M] = main run for this set of examples)

===> Index of Web pages and MPEG movies in table form

with pictures of initial situations (loads about 60 kb in total)

In text form:

• Some general information on the Finite Difference Method
  used in the program 'nsevol'.

• Computation with a Bessel monopole:
  • Self-organisation through interaction of 16 monopoles
    • initially placed symmetrical:
          - with stress-free walls
    • initially placed not symmetrical:
          - with stress-free walls
          - with no-slip walls
  • Bessel monopole on a beta-plane
  • Bessel monopole encounters a north-south ridge:
        - at the equator [M]
        - on the southern hemisphere
        - on the northern hemisphere
  • Bessel monopole encounters a circular mountain:
        - at the equator [M]
        - on the southern hemisphere
        - on the northern hemisphere
  • A Lamb dipole encounters a Bessel monopole
        --> see at "Lamb dipole" below

• Computation with a Lamb dipole:
  • Collision of two Lamb dipoles:
        - head-on
        - under 90 degrees
  • Lamb dipole in a domain with:
        - stress-free walls
        - no-slip walls
  • Lamb dipole crossing a ridge:
        - without background rotation [M]
        - with background rotation
  • A Lamb dipole encounters a Bessel monopole
    • with the monopole weaker than the dipole:
          - head-on: merger [M]
          - with an offset: temporal exchange of partners
    • with the monopole nearly as strong as the dipole:
          - head-on: strong merger
          - with an offset: exchange of partners

• Computation with a uniform monopole:
  • Formation of a tripolar vortex

• Study of the effect of a bottom topography:
  • Uniform flow across a mountain
  • Lamb dipole crossing a ridge:
        --> see at "Lamb dipole" above
  • Bessel monopole encounters a north-south ridge:
        --> see at "Bessel monopole" above
  • Bessel monopole encounters a circular mountain:
        --> see at "Bessel monopole" above

What's new on these pages? -- last change: 21 September 1999.

 

The research described on these pages falls in the category 'Fluid Dynamics' and its subcategories 'Vortex Dynamics' and 'Computational Fluid Dynamics'.

===> list of my publications about my Post-doc. research in Fluid Dynamics.

Starting 1 June 1996, I had a two-year post-doc. position in Dundee where I used the same numerical method for a research on the interaction between meddies and topography; see that page for some info on the background of that research.

Since June 1998 I am no longer working on this field of research; see my home page for details on what I am doing now.

By the way: A very nice example of a natural (monopolar) vortex that is of great importance is the Polar Vortex which forms over Antarctica in the Southern winter: the well-known "ozone hole" is closely linked to the existance of this Polar Vortex. See for some info my page on about ozone and the formation of the ozone hole and for pictures the page about the 1999 ozone hole as seen by GOME.

 
Jos van Geffen -- Home  |  Site Map  |  Contact Me

created: 25 September 1995
last modified: 26 May 2001