The Turbulent Flow, Low Re k-ε (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 numbers (typically less than 0.3).

The equations solved by the Turbulent Flow, Low Re k-ε interface are the Reynolds-averaged Navier–Stokes (RANS) equations for conservation of momentum and the continuity equation for conservation of mass. Turbulence effects are modeled using the AKN two-equation k-ε model with realizability constraints. The AKN model is a so-called low-Reynolds number model, which means that it can resolve the flow all the way down to the wall. The AKN model depends on the distance to the closest wall. The physics interface therefore includes a wall distance equation.

The Turbulent Flow, Low Re k-ε interface can be used for stationary and time-dependent analyses.

Except where included below, see The Laminar Flow Interface and The Turbulent Flow, k-ε Interface for all the other settings.

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

The Turbulence model property disables the Neglect inertial term (Stokes flow) check box, and for 2D components also the Shallow Channel Approximation check box.

The AKN model 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.

For this physics interface the parameters are Ce1, Ce2, Cμ, σk, σe, and κv.