These animations emphasize some typical features of vorticity dynamics for 2D and 3D slightly viscous flows.

They have been obtained by a combination of particle and finite-difference methods developped in our team. These tools are described in particular  in the following recent references:  

• Vortex Methods: theory and practice, G-H. Cottet and P. Koumoutsakos, Cambridge University Press, 2000.
• Blending finite-differences and particle methods for incompressible flow calculations, M.L. Ould-Salihi, G.-H. Cottet and M. El Hamraoui, SIAM J. Sci. Comp., 22, 1655-1674, 2000 (pdf file)
• Vortex methods with spatially varying cores,  G.-H. Cottet, P. Koumoutsakos and M. Ould-Salihi, J. Comp. Phys., 162, 164-185, 2000 (pdf  file)
• A comparison of spectral and votex methods, G.-H. Cottet, B. Michaux, S. Ossia and G. Vandenrlinden, J. Comp. Phys., 175, 2002 (pdf  file)
• Advances in direct numerical simulations of 3D wall-bounded flows vy Vortex-In-Cell methods, J. Comp. Phys., 193, 2004 (pdf file)