Fluid2d is a versatile Python-Fortran CFD code that solves a large class of 2D flows. It is designed to be used easily by Students learning Fluid Mechanics or Geophysical Fluid Dynamics and by their professors willing to illustrate their course and to organize numerical practicals. The idea is to visualize flows on the fly, as they are computed. The effect of parameter changes can be seen immediately. The key quantity of fluid2D is the vorticity. If you feel weak on vorticity dynamics, this code is for you. You should rapidly become as expert as the experts.
You can learn how basic processes work because of the power of animations. It is quite easy to go beyond textbooks and to reach research questions.
Project's homepage: http://pagesperso.univ-brest.fr/~roullet/fluid2d/