[foamWang]

Hi alberto,

Thank you for your explaination and I learnt from your posts.

In terms of your claim, I am not fully convinced.

In literature, I found some guy is using QUICK for LES, e.g.

1. Y. Zang, “On the Development of Tools for the Simulation of Geophysical Flows.” Ph.D Thesis, Stanford University (1995)
2. M. V. Salvetti, Y. Zang, R. L. Street, and S. Banerjee, “Large-eddy simulation of free-surface decaying turbulence with dynamic subgrid-scale models”, Phys. Fluids 9, 2405-19 (1997).
3. A. Cui and R. L. Street, “Large-Eddy Simulation of Coastal Upwelling Flow”, Environ. Fluid Mech. 4, 197-223 (2004).
4. Y. Zang and R. L. Street, “Numerical simulation of coastal upwelling and interfacial instability of a rotating and stratified fluid”, J. Fluid Mech. 305, 47-75 (1995).
5. L. L. Yuan, R. L. Street, and J. H. Ferziger, “Large-eddy simulations of a round jet in crossflow”, J. Fluid Mech. 379, 71-104 (1999).


They are using "Dynamic Mixed Model (DMM)".


I don't know whether the case is suitable to mention here. But please give comment.
BTW, I changed all the schemes back to Gauss linear with an improved grid. Now I get rid of the blow up problem using dynSmagorinsky and dynMixedSmagorinsky. My experience is that avoiding wedge cells and make the grid space increase as smooth as possible. Any sudden jump in grid space may lead to blow up.


I am comparing different LES model now and hope to get back with some posts.

Thanks.


roro

Originally Posted by alberto

QUICK is not a suitable scheme for LES, and the upwind scheme is even worse. They are too dissipative.

You should use linear, or higher order central schemes. Generally, avoid limited schemes, they're not a good choice if you want accurate LES.

If the solution "blows up" using the linear scheme, it is probably because your grid is not fine enough to have the local Pé < 2, as required by the scheme.

Best,