The role of subgrid scale (SOS) viscosity is investigated in LES and VMS-LES simulations of the flow around a circular cylinder at Re = 20000 on unstructured grids. The separation between the largest and the smallest resolved scales in the VMS formulation is obtained through a variational projection operator and finite-volume cell agglomeration. Two different non-dynamic eddy-viscosity SOS models are used both in classical LES and in VMS-LES. The sensitivity of the results to different parameters, such as the value of the SOS model input coefficient or the agglomeration level and to numerical viscosity in VMS-LES, is also addressed. Finally, a possible indicator of quality of the LES and VMS-LES predictions is examined.
Quality of classical and variational multiscale LES simulations of the flow around a circular cylinder
SALVETTI, MARIA VITTORIA;
2011-01-01
Abstract
The role of subgrid scale (SOS) viscosity is investigated in LES and VMS-LES simulations of the flow around a circular cylinder at Re = 20000 on unstructured grids. The separation between the largest and the smallest resolved scales in the VMS formulation is obtained through a variational projection operator and finite-volume cell agglomeration. Two different non-dynamic eddy-viscosity SOS models are used both in classical LES and in VMS-LES. The sensitivity of the results to different parameters, such as the value of the SOS model input coefficient or the agglomeration level and to numerical viscosity in VMS-LES, is also addressed. Finally, a possible indicator of quality of the LES and VMS-LES predictions is examined.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
