6.3
general documentation
cs_time_scheme_t Struct Reference

Time scheme descriptor. More...

#include <cs_parameters.h>

+ Collaboration diagram for cs_time_scheme_t:

Data Fields

int isto2t
 
double thetst
 

Detailed Description

Time scheme descriptor.

Members of the time scheme structure are publicly accessible, to allow for concise syntax, as they are expected to be used in many places.

Field Documentation

◆ isto2t

isto2t

Specifies the time scheme activated for the source terms of the turbulence equations i.e. related to $k$, $R_{ij}$, $\varepsilon$, $\omega$, $\varphi$, $\overline{f}$), apart from convection and diffusion.

  • 0: standard first-order: the terms which are linear functions of the solved variable are implicit and the others are explicit
  • 1: second-order: the terms of the form $S_i\phi$ which are linear functions of the solved variable $\phi$ are expressed as second-order terms by interpolation (according to the formula $(S_i\phi)^{n+\theta}=S_i^n[(1-\theta)\phi^n+\theta\phi^{n+1}]$, $\theta$ being given by the value of thetav associated with the variable $\phi$); the other terms $S_e$ are expressed as second-order terms by extrapolation (according to the formula $(S_e)^{n+\theta}=[(1+\theta)S_e^n-\theta S_e^{n-1}]$, $\theta$ being given by the value of thetst = 0.5)
  • 2: the linear terms $S_i\phi$ are treated in the same isto2t = 1; the other terms $S_e$ are way as when extrapolated according to the same formula as when isto2t = 1, but with $\theta$= thetst = 1.
    Due to certain specific couplings between the turbulence equations, isto2t is allowed the value 1 or 2 only for the $R_{ij}$ models (iturb = 30 or 31); hence, it is always initialised to 0.

◆ thetst

thetst

$ \theta $-scheme for the extrapolation of the nonlinear explicit source terms $S_e$ of the turbulence equations when the source term extrapolation has been activated (see isto2t), following the formula $(S_e)^{n+\theta}=(1+\theta)S_e^n-\theta S_e^{n-1}$.
The value of $theta$ is deduced from the value chosen for isto2t. Generally, only the value 0.5 is used.

  • 0 : explicit
  • 1/2: extrapolated in n+1/2
  • 1 : extrapolated in n+1

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