LES based on vorticityvelocity description
As we know that most LES codes(if not all) are based on the velocitypressure description of NavierStokes equations. Is it possible that such a code could be based on the vorticityvelocity description, i.e. vorticity transport equation plus the definition of vorticity? What are the difficulties in doing so? Thanks.

Re: LES based on vorticityvelocity description
There are no difficulties. In fact, since vorticity is the flow characteristic we are interested in most for turbulent flows, it only makes sense that we look at the velocityvorticity formulation (at least for incompressible flow). I have posted in the past the significant advantages of this formulation over the traditional methods.
Anyway, the dynamic LES formulation for the vorticityvelocity based NS has been presented in free space  no boundaries  for gridfree methods though there is nothing in the formulation that prevents one from using it for gridbased vorticityvelocity algorithms. Check the following JCP papers: Mansfield, Knio & Meneveau, A dynamic LES scheme for the vorticity transport equation: Formulation and a priori tests, JCP, vol 145, 693730, 1998 Mansfield, Knio & Meneveau, Dynamic LES of colliding vortex rings using a 3D vortex method, JCP, vol 152, 305345, 1999 Hope this helps Adrin Gharakhani 
Re: LES based on vorticityvelocity description
Hi,
I guess that the problem is to define wall boundary condition for the vorticity. 
Re: LES based on vorticityvelocity description
Hi there,
Mansfield, JR et. al recently conducted the dynamic LES of colliding vortex rings using a 3D vortex method. (J. Comput. Phys. 152: 305~345 (1999). The solution is based on the vorticityvelocity discription which you may be interested in. Hope this helps. Tony 
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