nutUTabulatedWallFunction

Table of Contents

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.

Required fields: 

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.

Further information

Source code