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gas_models » source

gas.c File Reference

Gas properties for state and thermodynamic equations and molecular transport properties. More...

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "../../util/source/compiler.h"
#include "../../util/source/useful.h"
#include "gas.h"
#include "tgas1.h"
#include "n2eq.h"
#include "co2eq.h"
#include "n2vibe.h"
#include "argon.h"
#include "lut.h"
#include "noneq/perf_gas_mix.h"
#include "noneq/mTg.h"

Defines

#define MAX_STEPS   30
#define MAX_RELATIVE_STEP   0.1
#define DBG_PT   0
#define DBG_RHOT   0
#define DBG_RHOP   0
#define HIGH_ORDER_DIFF   1
#define HIGH_ORDER_DIFF   1
#define EZERO   0.0
#define RA   (ideal_gas[0].R)
#define MA   (ideal_gas[0].M)
#define CVA   (ideal_gas[0].C_v)
#define CPA   (ideal_gas[0].C_p)
#define PRA   (ideal_gas[0].Prandtl)
#define RB   (ideal_gas[1].R)
#define MB   (ideal_gas[1].M)
#define CVB   (ideal_gas[1].C_v)
#define CPB   (ideal_gas[1].C_p)
#define PRB   (ideal_gas[1].Prandtl)
#define MAMB   (sqrt(ideal_gas[0].M / ideal_gas[1].M))
#define RA   (ideal_gas[0].R)
#define MA   (ideal_gas[0].M)
#define CVA   (ideal_gas[0].C_v)
#define CPA   (ideal_gas[0].C_p)
#define PRA   (ideal_gas[0].Prandtl)
#define RB   (ideal_gas[1].R)
#define MB   (ideal_gas[1].M)
#define CVB   (ideal_gas[1].C_v)
#define CPB   (ideal_gas[1].C_p)
#define PRB   (ideal_gas[1].Prandtl)
#define MAMB   (sqrt(ideal_gas[0].M / ideal_gas[1].M))
#define RA   (ideal_gas[0].R)
#define MA   (ideal_gas[0].M)
#define CVA   (ideal_gas[0].C_v)
#define CPA   (ideal_gas[0].C_p)
#define PRA   (ideal_gas[0].Prandtl)
#define RB   (ideal_gas[1].R)
#define MB   (ideal_gas[1].M)
#define CVB   (ideal_gas[1].C_v)
#define CPB   (ideal_gas[1].C_p)
#define PRB   (ideal_gas[1].Prandtl)
#define MAMB   (sqrt(ideal_gas[0].M / ideal_gas[1].M))
#define DEBUG_LUT_MIX   0
#define MIN_MOLES   0.0
#define MIN_MASS_FRAC   1.0e-30

Functions

int copy_gas_data (struct gas_data *src, struct gas_data *dest)
 Make a complete copy of the gas data.
int accumulate_gas_data (struct gas_data *src, struct gas_data *dest, double alpha)
 Accumulative copy of the gas data.
int print_gas_data (struct gas_data *src)
 Print all gas_state data to stdout.
double * copy_gas_data_to_buffer (struct gas_data *src, double *buf)
 Copy the abbreviated gas_data into a linear data buffer.
double * copy_buffer_to_gas_data (struct gas_data *dest, double *buf)
 Copy the abbreviated gas_data from a linear data buffer.
int number_of_values_in_gas_data_copy (void)
 Returns the number of double elements in each gas data copy.
int set_ideal_gas_properties (int i, double R, double Gamma, double Prandtl, double Lewis, double mu_ref, double T_ref, double S)
int set_type_of_gas (int gas_index)
 Selects the gas model.
int gas_type (void)
eosfn * get_EOS_function_pointer (void)
 Returns the pointer to the current equation of state function.
int get_number_of_species (void)
int get_number_of_vibrational_species (void)
int separate_electron_energy (void)
double gas_rhomin (void)
double gas_pmin (void)
double gas_amin (void)
double gas_Tmin (void)
double gas_Tmax (void)
gas_data * new_gas_data_struct (void)
int set_massf (struct gas_data *Q, int isp, double mf)
 Set the mass fraction for a particular species.
double get_massf (struct gas_data *Q, int isp)
 Get the mass fraction for a particular species.
double get_conc (struct gas_data *Q, int isp)
 Get the molar concentration for a particular species.
int set_Tvib (struct gas_data *Q, int isp, double Tvib)
 Set the vibrational temperature for a particular species.
double get_Tvib (struct gas_data *Q, int isp)
 Get the vibrational temperature for a particular species.
int set_evib (struct gas_data *Q, int isp, double evib)
 Set the vibrational energy for a particular species.
double get_evib (struct gas_data *Q, int isp)
 Get the vibrational energy for a particular species.
int EOS_rhoe (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Evaluate thermodynamic state from given density and specific internal energy.
int EOS_pT (struct gas_data *Q, int evaluate_visc_coeff)
 Compute the density, specific internal energy and local speed of sound from the pressure and temperature.
int EOS_rhoT (struct gas_data *Q, int evaluate_visc_coeff)
 Compute the gas properties from given density and temperature.
int EOS_rhop (struct gas_data *Q, int evaluate_visc_coeff)
 Compute the gas properties from given density and pressure.
double dTdp_const_rho (struct gas_data *Q)
 Compute the derivative of temperature wrt pressure.
double dTdrho_const_p (struct gas_data *Q)
 Compute the derivative of temperature wrt density.
int eos_ideal_gas_one_species (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Compute the pressure, temperature and local speed of sound from the density and the specific internal energy for a single-species ideal gas.
int eos_weird_167 (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 A strange nitrogen model to match DSMC calculations.
int eos_argon_power_law (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 An argon model with power-law viscosity to match DSMC calculations.
int eos_argon_lennard_jones (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 An argon model with Lennard-Jones viscosity and constants fitted to Chapman and Cowling's figure 10.
int eos_lut_one_species (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 A single-species gas using the look-up-table for properties.
int eos_lut_n_species (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Multiple-species mix where all properties come from a number of look-up-tables.
int eos_equil_air_tannehill (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Single-species mixture model for air.
int eos_equil_n2_paj (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Nitrogen in chemical equilibrium.
int eos_equil_co2_iaj (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Carbon-dioxide in chemical equilibrium.
int eos_equil_vib_n2 (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Nonreaction nitrogen but with vibrational energy in thermodynamic equilibrium.
int eos_ideal_gas_binary_mix (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Mix of two ideal gases.
int eos_equil_vib_n2_he_mix (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Mix of nitrogen (species 0) with equilibrium vibrational energy with ideal helium (species 1).
int eos_ionize_ar_n2_mix (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Mix of ideal nitrogen (species 0) with ionizing argon (species 1).
int eos_lut_mix (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Look-Up-Table for one species plus mix of perfect gases.
int eos_null_function (struct gas_data *Q, int use_T_guess, int evaluate_visc_coeff)
 Dummy function.
double fill_in_concentrations (int first_sp, int last_sp, double rho, double *f, double *mol_w, double *c)
double fill_in_mass_fractions (int first_sp, int last_sp, double rho, double *c, double *mol_w, double *f)

Detailed Description

Gas properties for state and thermodynamic equations and molecular transport properties. 

 * Revisions as gas.c...
 * ------------------
 * 28-Jan-96 : First built from pieces of physics.h, state.c
 *             and transprt.c.
 * 29-May-96 : put nsp into this module
 *             MAYBE_STATIC work vectors
 * 03-Nov-96 : Updated multi-species code.
 * 17-Nov-96 : merged viscous coefficients into the EOS calculation.
 * 05-Feb-97 : added Nitrogen in vibrational equilibrium
 * 08-Feb-97 : helium + nitrogen in vib. equil.
 * 01-Mar-97 : argon + air (perfect gases)
 * 16-Mar-97 : ionizing argon + inert nitrogen (vib. eq.)
 * 23-Mar-97 : mass fraction checking now done by decode_conserved()
 * 13-Apr-97 : optionally supply a guess for temperature
 * 22-Sep-97 : Number of species is set by set_type_of_gas()
 * 15-Oct-97 : Change pragmas to suit Cray
 * 01-Apr-99 : Added Look-up-table equation of state.
 * 12-Sep-99 : Two species gas using LUT
 * 26-Jul-02 : mixture of perfect gases ( R.Gollan )
 * 28-Sep-02 : Moved to cfd/gas_models/source; separated from mb_cns
 * 2004      : MPI buffer copies, more access for scripting languages.
 * 12-Sep-05 : extra functions for Daniel's Riemann solver
 *

Note:
Have removed most high temperature warnings. I think that the functions should just deal as well as they can with higher than expected temperatures. (am thinking of a couple of hundred-thousand degrees K, not millions and above)
Author:
PA Jacobs

Function Documentation

int accumulate_gas_data (  struct gas_data *  src,
struct gas_data *  dest,
double  alpha
)  [inline]
 

Accumulative copy of the gas data.

Typically used in the CFD code to replace bad-cell data.

double* copy_buffer_to_gas_data (  struct gas_data *  dest,
double *  buf
)  [inline]
 

Copy the abbreviated gas_data from a linear data buffer.

Parameters:
dest,: pointer to the gas_data structure
buf : pointer to the current element somewhere in buffer
Returns:
a pointer to the next available location in the data buffer.

int copy_gas_data (  struct gas_data *  src,
struct gas_data *  dest
)  [inline]
 

Make a complete copy of the gas data.

Typically used in the CFD code to make ghost-cell copies.

double* copy_gas_data_to_buffer (  struct gas_data *  src,
double *  buf
)  [inline]
 

Copy the abbreviated gas_data into a linear data buffer.

Parameters:
src : pointer to the gas_data structure
buf : pointer to the current element somewhere in buffer
Returns:
a pointer to the next available location in the data buffer.

double dTdp_const_rho (  struct gas_data *  Q  ) 
 

Compute the derivative of temperature wrt pressure.

Parameters:
Q : pointer to the gas_data structure already containing desired pressure and density.
Returns:
: approximation to derivative.
Note:
The gas state properties may be mangled by this function.

double dTdrho_const_p (  struct gas_data *  Q  ) 
 

Compute the derivative of temperature wrt density.

Parameters:
Q : pointer to the gas_data structure already containing desired pressure and density.
Returns:
: approximation to derivative.
Note:
The gas state properties may be mangled by this function.

int eos_ideal_gas_one_species (  struct gas_data *  Q,
int  use_T_guess,
int  evaluate_visc_coeff
) 
 

Compute the pressure, temperature and local speed of sound from the density and the specific internal energy for a single-species ideal gas.

Parameters:
Q : pointer to the gas_data structure
use_T_guess : 0 : don't use Q.T as a guess for Temperature 1 : Q.T is available as an initial guess
 * Also, the following elements of the gas state are updated...
 * p      : pressure in Pa
 * T      : absolute temperature, degrees K
 * a      : sound speed, m/s
 *
 * ...and, if the viscous_flag is set...
 * mu     : molecular viscosity in Pa.s
 * lmbda : second viscosity coefficient, Pa.s
 * k      : thermal conductivity coefficient
 *

Returns:
0 if all is OK, 1 otherwise.

int eos_lut_mix (  struct gas_data *  Q,
int  use_T_guess,
int  evaluate_visc_coeff
) 
 

Look-Up-Table for one species plus mix of perfect gases. 

 * The so-called-species are:
 *     0 LUT
 *     1 argon
 *     2 helium
 *     3 nitrogen
 *     4 air
 * This arrangement (of having LUT as species 0) allows us 
 * to drop back to using the eos_lut_one_species() function 
 * when the LUT gas is the only significant component.
 *

int eos_lut_n_species (  struct gas_data *  Q,
int  use_T_guess,
int  evaluate_visc_coeff
) 
 

Multiple-species mix where all properties come from a number of look-up-tables.

Note that only one table at a time provides the gas-mix properties. This table is determined by the dominant species (as measured by mass fraction).

int eos_lut_one_species (  struct gas_data *  Q,
int  use_T_guess,
int  evaluate_visc_coeff
) 
 

A single-species gas using the look-up-table for properties.

Note that a mix of gases in chemical equilibrium is handled by this model. Use the Chemical Equilibrium Analysis program from NASA Glenn to generate the table. The programs cea_driver.tcl and cea_to_binary.c are provided to automate the table generation process.

int EOS_pT (  struct gas_data *  Q,
int  evaluate_visc_coeff
) 
 

Compute the density, specific internal energy and local speed of sound from the pressure and temperature.

The process used is going to be a bit slow but this function is not intended for use within the inner loops of the simulation code.

Parameters:
Q : pointer to the gas_data structure
Returns:
: a value of 0 if all is OK, 1 if something goes wrong.

int EOS_rhoe (  struct gas_data *  Q,
int  use_T_guess,
int  evaluate_visc_coeff
) 
 

Evaluate thermodynamic state from given density and specific internal energy.

This is a convenience function so that we don't always have to deal with function pointers. The real work is delegated to the specialized EOS functions, one for each gas model.

Parameters:
Q : pointer to the gas data structure
use_T_guess : ==1 use the given value of temparature as a starting guess, if necessary.
evaluate_visc_coeff : ==1 to invoke the calculation of the viscous transport coefficients
Returns:
0 on success nonzero for failure

int EOS_rhop (  struct gas_data *  Q,
int  evaluate_visc_coeff
) 
 

Compute the gas properties from given density and pressure.

The process used is going to be a bit slow but this function is not intended for use within the inner loops of the simulation code.

Parameters:
Q : pointer to the gas_data structure
Returns:
: a value of 0 if all is OK, 1 if something goes wrong.

int EOS_rhoT (  struct gas_data *  Q,
int  evaluate_visc_coeff
) 
 

Compute the gas properties from given density and temperature.

The process used is going to be a bit slow but this function is not intended for use within the inner loops of the simulation code.

Parameters:
Q : pointer to the gas_data structure
Returns:
: a value of 0 if all is OK, 1 if something goes wrong.

double get_conc (  struct gas_data *  Q,
int  isp
) 
 

Get the molar concentration for a particular species.

This function is mainly to allow convenient access from the SWIG interface.

eosfn* get_EOS_function_pointer (  void   )  [inline]
 

Returns the pointer to the current equation of state function.

The CFD functions can then invoke the appropriate EOS for the gas model.

double get_evib (  struct gas_data *  Q,
int  isp
) 
 

Get the vibrational energy for a particular species.

This function is mainly to allow convenient access from the SWIG interface.

double get_massf (  struct gas_data *  Q,
int  isp
) 
 

Get the mass fraction for a particular species.

This function is mainly to allow convenient access from the SWIG interface.

double get_Tvib (  struct gas_data *  Q,
int  isp
) 
 

Get the vibrational temperature for a particular species.

This function is mainly to allow convenient access from the SWIG interface.

int number_of_values_in_gas_data_copy (  void   )  [inline]
 

Returns the number of double elements in each gas data copy.

We need this to work out where we should be in the buffer for each copy.

int set_evib (  struct gas_data *  Q,
int  isp,
double  evib
) 
 

Set the vibrational energy for a particular species.

This function is mainly to allow convenient access from the SWIG interface.

int set_massf (  struct gas_data *  Q,
int  isp,
double  mf
) 
 

Set the mass fraction for a particular species.

This function is mainly to allow convenient access from the SWIG interface.

int set_Tvib (  struct gas_data *  Q,
int  isp,
double  Tvib
) 
 

Set the vibrational temperature for a particular species.

This function is mainly to allow convenient access from the SWIG interface.

int set_type_of_gas (  int  gas_index  ) 
 

Selects the gas model.

This is done by setting the gas model equation-of-state pointer and a few other gas-model specific constants.

Parameters:
gas_index,: look up gas.h to see the allowable values.

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