8.3
general documentation
Modules | Data Types | Variables
Compressible models options
General module for specific physics
+ Collaboration diagram for Compressible models options:

Modules

 Homogeneous two-phase compressible model options
 

Data Types

struct  cs_cf_model_t
 Compressible model general options descriptor. More...
 

Variables

integer, save ienerg
 specific total energy for compressible algorithm More...
 
integer, save itempk
 temperature deduced from the specific total energy More...
 
int ieos
 
int ithvar
 
int icfgrp
 
double psginf
 
double gammasg
 

Detailed Description

\ defgroup compressible Compressible models options

Variable Documentation

◆ gammasg

gammasg

stiffened gas polytropic coefficient (dimensionless) for single phase model

◆ icfgrp

icfgrp

indicator for hydrostatic balance in boundary conditions

In the cases where gravity is predominant, taking into account the hydrostatic pressure allows to get rid of perturbations which may appear near the horizontal walls when the flow is weakly convective.

Otherwise, when icfgrp=0, the pressure condition is calculated from the solution of the unidimensional Euler equations for a perfect gas near a wall, for the variables "normal velocity", "density" and "pressure":

Case of an expansion (M <= 0):

\begin{align*} P_p &= 0 & \textrm{if } 1 + \displaystyle\frac{\gamma-1}{2}M<0 \\ P_p &= P_i \left(1 + \displaystyle\frac{\gamma-1}{2}M\right) ^{\frac{2\gamma}{\gamma-1}} & \textrm{otherwise} \end{align*}

Case of a schock (M > 0):

\begin{eqnarray*} P_p = P_i \left(1 + \displaystyle\frac{\gamma(\gamma+1)}{4}M^2 +\gamma M \displaystyle\sqrt{1+\displaystyle\frac{(\gamma+1)^2}{16}M^2}\right) \end{eqnarray*}

with $M = \displaystyle\frac{\vect{u}_i \cdot \vect{n}}{c_i}$, internal Mach number calculated with the variables taken in the cell.

◆ ienerg

integer, save ienerg

specific total energy for compressible algorithm

◆ ieos

ieos

indicator of equation of state

  • CS_EOS_IDEAL_GAS: ideal gas with a constant adiabatic coefficient
  • CS_EOS_STIFFENED_GAS: stiffened gas
  • CS_EOS_GAS_MIX: mix of ideal gas
  • CS_EOS_HOMOGENEOUS_TWO_PHASE: two-phase homogeneous model only, each phase follows a stiffened gas law.
  • CS_EOS_MOIST_AIR: moist air equation of state with condensable (mixture of two ideal gas)

◆ itempk

integer, save itempk

temperature deduced from the specific total energy

◆ ithvar

ithvar

indicator for thermodynamic variables initialization

◆ psginf

psginf

stiffened gas limit pressure (zero in perfect gas) for single phase model in Pa