The Turbulent Flow, L-VEL (spf) interface () is used for simulating single-phase flows at high Reynolds numbers. The physics interface is suitable for incompressible flows, weakly compressible flows, and compressible flows at low Mach number (typically less than 0.3).

The equations solved by the Turbulent Flow, L-VEL interface are the Reynolds-averaged Navier–Stokes (RANS) equations for conservation of momentum and the continuity equation for conservation of mass. Turbulence effects are included using an enhanced viscosity model based on the local wall distance, and the physics interface therefore includes a wall distance equation. When this physics interface is added, the following default nodes are also added in the Model Builder — Fluid Properties, Wall (the default boundary condition is No slip), and Initial Values. Except where included below, see The Laminar Flow Interface and The Turbulent Flow, k-ε Interface for all the other settings.

With the addition of various modules, the Enable porous media domains check box is available. Selecting this option, a Fluid and Matrix Properties node, a Mass Source node, and a Forchheimer Drag subnode are added to the physics interface. These are described for the Brinkman Equations interface in the respective module’s documentation. Applying the Fluid and Matrix Properties on a subset of the domains enables studies of coupled porous-media flow and turbulent flow.

A different turbulence model can be selected under Turbulence model. Laminar or creeping flow may simulated by changing the Turbulence model type to None.

L-VEL employs per default an Automatic wall treatment, which switches between a low-Reynolds-number formulation and a wall function formulation depending on how well resolved the flow is close to the wall. The automatic wall treatment gives a robust formulation that makes the most out of the available resolution. Select the Low Re option in order to enforce resolution all the way down to the wall. This can be more accurate than the automatic wall treatment provided that the mesh is fine enough.

Turbulence model parameters, κl and El, have been optimized for internal flow. For certain cases, better performance can be obtained by tuning the model parameters. The turbulence model parameters can be tuned when the Edit turbulence model parameters check box is selected.