A new hybrid RANS/LES approach is presented.
The key feature of this approach is a blending between
two eddy-viscosities, one given by the k-\epsilon RANS
model and the other by the Smagorinsky VMS-LES
(variational multiscale LES) closure. The blending
is set by a parameter theta: VMS-LES mode is active when theta=0,
RANS mode if theta=1, a hybrid mode for 0<theta<1.
The hybrid model is applied to the simulation of the flow
around a circular cylinder at Re=140000, testing the sensitivity of the model to blending parameter variations, to grid refinements and to preconditioning changes.
The results are also compared with those obtained using the detached eddy simulation (DES) approach and with experimental data avaible in the literature .