In openFOAM, there are multiple options for choose in LES, such as WALE model, Smagorinsky model and so on. Which one is suitable for dynamic mesh and why ?
I am a bigginner of LES simulation, as far as I know , the only difference between them is WALE model includes the rotation rate in the calculation of νsgs, and Smagorinsky not. What else should I take into account in simulation?
Different simulation tasks may require different turbulence models. I suggest, you look for literature on your application (or similar applications) as a reference case. And either rely on previous work or do test runs with different models to see which one gets you closest to replicating the reference case.
Hong Xiang Yu
In general, for dynamic mesh simulations, models that involve additional terms in the turbulence kinetic energy equation, such as WALE (Wall-adapting Local Eddy-Viscosity) or dynamic Smagorinsky, may be more suitable. These models account for the effects of mesh deformation on the turbulence field and can improve the accuracy of the simulations.
WALE model includes additional terms in the eddy-viscosity calculation that account for the effects of rotation rate, strain rate, and dissipation rate. This model can be more accurate for complex flows with high strain rates and rotation rates, such as flows with vortices or swirling motions.
On the other hand, the Smagorinsky model is a popular choice for LES simulations in OpenFOAM and is widely used for a range of flows. This model uses a constant eddy viscosity coefficient that is proportional to the grid size, which means that it can be computationally efficient for large-scale simulations. However, it may not be as accurate for complex flows or when mesh deformation effects are significant.
When choosing an LES model for dynamic mesh simulations, it is important to consider the specific characteristics of the flow and the desired level of accuracy. It is also recommended to perform sensitivity studies to investigate the effect of different LES models on the results and to validate the simulations against experimental data or other established methods.
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