The LES RBVMWV Interface
The LES RBVMWV (spf) interface () is used for simulating single-phase flows at high Reynolds numbers by resolving the larger three-dimensional unsteady eddies and modeling the effect of the smaller eddies. The physics interface is currently only suitable for incompressible flows.
The equations solved by the LES RBVMWV interface are the continuity equation for conservation of mass and the Navier-Stokes equation, augmented by additional stress terms, for conservation of momentum. Similar modeling as for the LES RBVM model is applied but the effect of the Reynolds stress is enhanced by adding a turbulent viscosity term. Since the modeling is consistent, the interface is also applicable to laminar and transitional flows.
The LES RBVMWV interface should only be used for three-dimensional, time-dependent analyses. The main feature is Fluid Properties, which adds the Navier-Stokes and continuity equations, and provides an interface for defining the fluid material and its properties. When this physics interface is added, the following default nodes are also added in the Model Builder: Fluid Properties, Initial Values, and Wall.
Except where included below, see The Laminar Flow Interface for all the other settings.
Turbulence
A different LES model can be selected under Turbulence model. A RANS turbulence model can be selected by changing the Turbulence model type to RANS. Laminar or creeping flow may be simulated by changing the Turbulence model type to None.
The Turbulence model property disables the Neglect inertial term (Stokes flow) check box and Enable porous media domains check box.
Use dynamic subgrid time scale
Enable this check box to use the time derivative from the previous time step to estimate temporal changes in the unresolved scales.
Edit LES Model Parameters
Turbulence model parameters are optimized to fit as many flow types as possible, but for some special cases, better performance can be obtained by tuning the model parameters.
For this physics interface the turbulent viscosity parameter is .
Dependent Variables
The following dependent variables (fields) are defined for this physics interface:
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Velocity field u and its components
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Pressure p
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The Laminar Flow Interface
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Theory for the Large Eddy Simulation Interfaces