The open source CFD toolbox
nutUTabulatedWallFunction

Properties

• The nutUTabulatedWallFunction boundary condition provides a wall constraint on the turbulent viscosity, i.e. nut, based on velocity, i.e. U, for low- and high-Reynolds number turbulence models.
• As input, the user specifies a look-up table of u+ as a function of near-wall Reynolds number.
• The look-up table should be located in the \$FOAM_CASE/constant directory.
• The nutUTabulatedWallFunction condition inherits the traits of the nutWallFunction boundary condition.

nut  | Turbulent viscosity         [m2/s]


Model equations

The model expressions:

$\nu_t = \max(0, \frac{\left( \frac{u_p}{u^+ + \zeta} \right)^2}{|\grad{\u}| + \zeta} - \nu_w )$

where

 $$\nu_t$$ = Turbulent viscosity [m2/s] $$\nu_w$$ = Kinematic viscosity of fluid near wall [m2/s] $$u_p$$ = Magnitude of velocity near wall [m/s] $$u^+$$ = Tabulated velocity near wall in wall units $$\u$$ = Velocity near wall [m/s] $$\zeta$$ = Small value to prevent floating point exceptions

Usage

Example of the boundary condition specification:

<patchName>
{
// Mandatory entries (unmodifiable)
type            nutUTabulatedWallFunction;
uPlusTable      myUPlusTable;

// Optional (inherited) entries
...
}


where the entries mean:

Property Description Type Required Default
type Type name: nutUTabulatedWallFunction word yes -
uPlusTable u+ as a function of Re table name word yes -

The inherited entries are elaborated in:

Notes on entries

• The inherited wall-function blending methods are not available for this wall function.

Source code