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Fluid properties descriptor. More...
#include <cs_physical_constants.h>
Data Fields | |
int | ixyzp0 |
double | ro0 |
double | viscl0 |
double | p0 |
double | pred0 |
double | xyzp0 [3] |
double | t0 |
double | cp0 |
double | xmasmr |
double | pther |
double | pthera |
double | pthermax |
Fluid properties descriptor.
Members of these fluid properties are publicly accessible, to allow for concise syntax, as they are expected to be used in many places.
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.
ixyzp0 |
filling xyzp0 indicator
p0 |
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.
pther |
uniform thermodynamic pressure for the low-Mach algorithm
Thermodynamic pressure for the current time step.
pthera |
thermodynamic pressure for the previous time step
pthermax |
thermodynamic maximum pressure for user clipping, used to model a venting effect
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 subroutines 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.
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.
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.
xmasmr |
molar mass of the perfect gas in (if ieos=1)
Always useful.
xyzp0[3] |
coordinates of the reference point for the total pressure
Always useful, except with the compressible module.