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cs_wall_functions_t Struct Reference

wall functions descriptor. More...

#include <cs_wall_functions.h>

Collaboration diagram for cs_wall_functions_t:

Data Fields

cs_wall_f_type_t iwallf
cs_wall_f_s_type_t iwalfs
double ypluli

Detailed Description

wall functions descriptor.

Members of this wall functions descriptor are publicly accessible, to allow for concise syntax, as it is expected to be used in many places.

Field Documentation

◆ iwalfs

cs_wall_f_s_type_t iwalfs

wall functions for scalar

  • CS_WALL_F_S_ARPACI_LARSEN: three layers (Arpaci and Larsen) or two layers (Prandtl-Taylor) for Prandtl number smaller than 0.1
  • CS_WALL_F_S_VDRIEST: consistant with the 2 scales wall function for velocity using Van Driest mixing length
  • CS_WALL_F_S_LOUIS: default wall function for atmospheric flows for potential temperature. This has influence on the dynamic.
  • CS_WALL_F_S_MONIN_OBUKHOV: Monin Obukhov wall function for atmospheric flows for potential temperature. This has influence on the dynamic.

◆ iwallf

cs_wall_f_type_t iwallf

Indicates the type of wall function used for the velocity boundary conditions on a frictional wall.

  • CS_WALL_F_DISABLED: no wall functions
  • CS_WALL_F_1SCALE_POWER: one scale of friction velocities (power law)
  • CS_WALL_F_1SCALE_LOG: one scale of friction velocities (log law)
  • CS_WALL_F_2SCALES_LOG: two scales of friction velocities (log law)
  • CS_WALL_F_SCALABLE_2SCALES_LOG: two scales of friction velocities (log law) (scalable wall functions)
  • CS_WALL_F_2SCALES_VDRIEST: two scales of friction velocities (mixing length based on V. Driest analysis)
  • CS_WALL_F_2SCALES_SMOOTH_ROUGH: wall function unifying rough and smooth friction regimes
  • CS_WALL_F_2SCALES_CONTINUOUS: All $ y^+ $ for low Reynolds models
    iwallf is initialised to CS_WALL_F_1SCALE_LOG for model = 10, 40, 41 or 70 (mixing length, LES and Spalart Allmaras).
    iwallf is initialised to CS_WALL_F_DISABLED for model = 0, 32, 50 or 51
    iwallf is initialised to CS_WALL_F_2SCALES_LOG for model = 20, 21, 30, 31 or 60 ( $k-\epsilon$, $R_{ij}-\epsilon$ LRR, $R_{ij}-\epsilon$ SSG and $k-\omega$ SST models).
    The v2f model (model=50) is not designed to use wall functions (the mesh must be low Reynolds).
    The value iwallf = CS_WALL_F_2SCALES_LOG is not compatible with model=0, 10, 40 or 41 (laminar, mixing length and LES).
    Concerning the $k-\epsilon$ and $R_{ij}-\epsilon$ models, the two-scales model is usually at least as satisfactory as the one-scale model.
    The scalable wall function allows to virtually shift the wall when necessary in order to be always in a logarithmic layer. It is used to make up for the problems related to the use of High-Reynolds models on very refined meshes.
    Useful if model is different from 50.

◆ ypluli

double ypluli

limit value of $y^+$ for the viscous sublayer

ypluli depends on the chosen wall function: it is initialized to 10.88 for the scalable wall function (iwallf=CS_WALL_F_SCALABLE_2SCALES_LOG), otherwise it is initialized to $1/\kappa\approx 2,38$. In LES, ypluli is taken by default to be 10.88. Always useful.

The documentation for this struct was generated from the following files: