Module for physical constants

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Modules | Variables
Module for physical constants
Collaboration diagram for Module for physical constants:

## Modules
| Module for turbulence constants

## Variables
double precision | tkelvi
| Temperature in Kelvin correponding to 0 degrees Celsius (= +273,15) More...
double precision | tkelvn
| Temperature in degrees Celsius corresponding to 0 Kelvin (= -273,15) More...
double precision | xcal2j
| Calories (1 cal = xcal2j J) More...
double precision | stephn
| Stephan constant for the radiative module in . More...
double precision | rair
| Perfect gas constant for air (mixture) More...
double precision, save | gx
| Gravity. More...
double precision, save | gy
double precision, save | gz
integer, save | icorio
double precision, save | omegax
| Rotation vector. More...
double precision, save | omegay
double precision, save | omegaz
double precision, dimension(3, 3), save | irot
double precision, dimension(3, 3), save | prot
double precision, dimension(3, 3), save | qrot
double precision, dimension(3, 3), save | rrot
integer, save | ixyzp0
| Constantes physiques du fluide filling xyzp0 indicator. More...
double precision, save | ro0
| reference density. Negative value: not initialised. Its value is not used in gas or coal combustion modelling (it will be calculated following the perfect gas law, with and ). With the compressible module, it is also not used by the code, but it may be (and often is) referenced by the user in user subroutines; it is therefore better to specify its value. More...
double precision, save | viscl0
| reference molecular dynamic viscosity. Negative value: not initialised. More...
double precision, save | p0
| reference pressure for the total pressure. except with the compressible module, the total pressure is evaluated from the reduced pressure so that is equal to p0 at the reference position (given by xyzp0). with the compressible module, the total pressure is solved directly. always Useful More...
double precision, save | pred0
| reference value for the reduced pressure (see ro0). It is especially used to initialise the reduced pressure and as a reference value for the outlet boundary conditions. For an optimised precision in the resolution of , it is wiser to keep pred0 to 0. With the compressible module, the "pressure" variable appearing in the equations directly represents the total pressure. It is therefore initialised to p0 and not pred0 (see ro0). Always useful, except with the compressible module More...
double precision, dimension(3), save | xyzp0
| coordinates of the reference point for the total pressure. More...
double precision, save | t0
| reference temperature. More...
double precision, save | cp0
| reference specific heat. More...
double precision, save | xmasmr
| molar mass of the perfect gas in (if ieos=1) More...
double precision, save | pther
| Uniform thermodynamic pressure for the low-Mach algorithm Thermodynamic pressure for the current time step. More...
double precision, save | pthera
| Thermodynamic pressure for the previous time step. More...

## Detailed Description

## Variable Documentation

double precision, save cp0

reference specific heat.

Useful if there is 1 <= n <= nscaus. So that iscsth(n)=1 (there is a scalar "temperature"), unless the user specifies the specific heat in the user subroutine {usphyv} (icp > 0) with the compressible module or coal combustion, cp0 is also needed even when there is no user scalar.

Note
  None of the scalars from the specific physics is a temperature.
  When using the Graphical Interface, cp0 is also used to calculate the diffusivity of the thermal scalars, based on their conductivity; it is therefore needed, unless the diffusivity is also specified in usphyv.

double precision, save gx

Gravity.

double precision, save gy

double precision, save gz

integer, save icorio

double precision, dimension(3,3), save irot

integer, save ixyzp0

Constantes physiques du fluide filling xyzp0 indicator.

double precision, save omegax

Rotation vector.

double precision, save omegay

double precision, save omegaz

double precision, save p0

reference pressure for the total pressure. except with the compressible module, the total pressure is evaluated from the reduced pressure so that is equal to p0 at the reference position (given by xyzp0). with the compressible module, the total pressure is solved directly. always Useful

double precision, save pred0

reference value for the reduced pressure (see ro0). It is especially used to initialise the reduced pressure and as a reference value for the outlet boundary conditions. For an optimised precision in the resolution of , it is wiser to keep pred0 to 0. With the compressible module, the "pressure" variable appearing in the equations directly represents the total pressure. It is therefore initialised to p0 and not pred0 (see ro0). Always useful, except with the compressible module

double precision, dimension(3,3), save prot

double precision, save pther

Uniform thermodynamic pressure for the low-Mach algorithm Thermodynamic pressure for the current time step.

double precision, save pthera

Thermodynamic pressure for the previous time step.

double precision, dimension(3,3), save qrot

double precision rair

Perfect gas constant for air (mixture)

double precision, save ro0

reference density. Negative value: not initialised. Its value is not used in gas or coal combustion modelling (it will be calculated following the perfect gas law, with and ). With the compressible module, it is also not used by the code, but it may be (and often is) referenced by the user in user subroutines; it is therefore better to specify its value.

Always useful otherwise, even if a law defining the density is given by the user subroutine usphyv or uselph. indeed, except with the compressible module, CS does not use the total pressure when solving the Navier-Stokes equation, but a reduced pressure . . where is a reference point (see xyzp0) and and are reference values (see pred0 and p0). Hence, the term in the equation is treated as . The closer ro0 is to the value of , the more will tend to represent only the dynamic part of the pressure and the faster and more precise its solution will be. Whatever the value of ro0, both and appear in the listing and the post-processing outputs.. with the compressible module, the calculation is made directly on the total pressure

double precision, dimension(3,3), save rrot

double precision stephn

Stephan constant for the radiative module in .

double precision, save t0

reference temperature.

Useful for the specific physics gas or coal combustion (initialisation of the density), for the electricity modules to initialise the domain temperature and for the compressible module (initialisations). It must be given in Kelvin.

double precision tkelvi

Temperature in Kelvin correponding to 0 degrees Celsius (= +273,15)

double precision tkelvn

Temperature in degrees Celsius corresponding to 0 Kelvin (= -273,15)

double precision, save viscl0

reference molecular dynamic viscosity. Negative value: not initialised.

Always useful, it is the used value unless the user specifies the viscosity in the subroutine usphyv

double precision xcal2j

Calories (1 cal = xcal2j J)

double precision, save xmasmr

molar mass of the perfect gas in (if ieos=1)

Always useful

double precision, dimension(3), save xyzp0

coordinates of the reference point for the total pressure.

- When there are no Dirichlet conditions for the pressure (closed domain), xyzp0 does not need to be specified (unless the total pressure has a clear physical meaning in the configuration treated).
- When Dirichlet conditions on the pressure are specified but only through stantard outlet conditions (as it is in most configurations), xyzp0 does not need to be specified by the user, since it will be set to the coordinates of the reference outlet face (i.e. the code will automatically select a reference outlet boundary face and set xyzp0 so that equals p0 at this face). Nonetheless, if xyzp0 is specified by the user, the calculation will remain correct.
- When direct Dirichlet conditions are specified by the user (specific value set on specific boundary faces), it is better to specify the corresponding reference point (i.e. specify where the total pressure is p0). This way, the boundary conditions for the reduced pressure will be close to pred0, ensuring an optimal precision in the resolution. If xyzp0 is not specified, the reduced pressure will be shifted, but the calculations will remain correct..
- With the compressible module, the "pressure" variable appearing in the equations directly represents the total pressure. xyzp0 is therefore not used..

Always useful, except with the compressible module.