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cantera/src/tpx/CarbonDioxide.cpp
Ray Speth 2528df0f75 Reorganized source tree structure 
These changes make it unnecessary to copy header files around during
the build process, which tends to confuse IDEs and debuggers. The
headers which comprise Cantera's external C++ interface are now in
the 'include' directory.

All of the samples and demos are now in the 'samples' subdirectory.
2012-02-12 02:27:14 +00:00

401 lines
8.8 KiB
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/* FILE: CarbonDioxide.cpp
* DESCRIPTION:
* representation of substance Carbon Dioxide
* values and functions are from
* "Thermodynamic Properties in SI" bu W.C. Reynolds
* AUTHOR: me@rebeccahhunt.com: GCEP, Stanford University
*
*/
#include "CarbonDioxide.h"
#include <math.h>
#include <string.h>
namespace tpx
{
/*
* Carbon Dioxide constants
*/
static const double Tmn = 216.54; // [K] minimum temperature for which calculations are valid
static const double Tmx = 1500.0; // [K] maximum temperature for which calculations are valid
static const double Tc=304.21; // [K] critical temperature
static const double Roc=464.00; // [kg/m^3] critical density
static const double To=216.54; // [K] reference Temperature
static const double R=188.918; // [] gas constant for CO2 J/kg/K
static const double Gamma=5.0E-6; // [??]
static const double u0=3.217405E5; // [] internal energy at To
static const double s0=2.1396056E3; // [] entropy at To
static const double Tp=250; // [K] ??
//static const double Pc=7.38350E6; // [Pa] critical pressure
static const double Pc=7.3817589E6; // Adjusted to fit the actual functional form
static const double M=44.01; // [kg/kmol] molar density
/*
* array Acarbdi is used by the function named Pp
*/
static const double Acarbdi[]= {
2.2488558E-1,
-1.3717965E2,
-1.4430214E4,
-2.9630491E6,
-2.0606039E8,
4.5554393E-5,
7.7042840E-2,
4.0602371E1,
4.0029509E-7,
-3.9436077E-4,
1.2115286E-10,
1.0783386E-7,
4.3962336E-11,
-3.6505545E4,
1.9490511E7,
-2.9186718E9,
2.4358627E-2,
-3.7546530E1,
1.1898141E4
};
/*
* array F is used by the function named Psat
*/
static const double F[]= {
-6.5412610,
-2.7914636E-1,
-3.4716202,
-3.4989637,
-1.9770948E1,
1.3922839E2,
-2.7670389E2,
-7.0510251E3
};
/*
* array D is used by the function ldens
*/
static const double D[]= {
4.6400009E2,
6.7938129E2,
1.4776836E3,
-3.1267676E3,
3.6397656E3,
-1.3437098E3
};
/*
* array G is used by the function sp
*/
static const double G[]= {
8.726361E3,
1.840040E2,
1.914025,
-1.667825E-3,
7.305950E-7,
-1.255290E-10,
3.2174105E5,
2.1396056E3
};
/*
* C returns a multiplier in each term of the sum
* in P-3, used in conjunction with C in the function Pp
* j is used to represent which of the values in the summation to calculate
* j=0 is the second additive in the formula in reynolds
* j=1 is the third...
* (this part does not include the multiplier rho^n)
*/
double CarbonDioxide::C(int j,double Tinverse, double T2inverse, double T3inverse, double T4inverse)
{
switch (j) {
case 0 :
return Acarbdi[0]*T +
Acarbdi[1] +
Acarbdi[2] * Tinverse +
Acarbdi[3] * T2inverse +
Acarbdi[4] * T3inverse ;
case 1 :
return Acarbdi[5] *T +
Acarbdi[6] +
Acarbdi[7] * Tinverse ;
case 2 :
return Acarbdi[8]*T + Acarbdi[9];
case 3 :
return Acarbdi[10]*T + Acarbdi[11];
case 4 :
return Acarbdi[12];
case 5 :
return Acarbdi[13] *T2inverse +
Acarbdi[14] *T3inverse +
Acarbdi[15] *T4inverse;
case 6 :
return Acarbdi[16] *T2inverse +
Acarbdi[17] *T3inverse +
Acarbdi[18] *T4inverse;
default :
return 0.0;
}
}
/* cprime
* derivative of C(i)
*/
inline double CarbonDioxide::Cprime(int j, double T2inverse, double T3inverse, double T4inverse)
{
switch (j) {
case 0 :
return Acarbdi[0] +
- Acarbdi[2] * T2inverse +
-2 * Acarbdi[3] * T3inverse +
-3 * Acarbdi[4] * T4inverse ;
case 1 :
return Acarbdi[5] -
Acarbdi[7] * T2inverse;
case 2 :
return Acarbdi[8] ;
case 3 :
return Acarbdi[10] ;
case 4 :
return 0;
case 5 :
return
-2 *Acarbdi[13] *T3inverse +
-3 *Acarbdi[14] *T4inverse +
-4 *Acarbdi[15]* pow(T,-5);
case 6 :
return
-2 *Acarbdi[16] *T3inverse +
-3 *Acarbdi[17] *T4inverse +
-4 *Acarbdi[18] *pow(T,-5);
default :
return 0.0;
}
}
/*
* I = integral from o-rho { 1/(rho^2) * H(i, rho) d rho }
* ( see section 2 of Reynolds TPSI )
*/
inline double CarbonDioxide::I(int j, double ergho, double Gamma)
{
switch (j) {
case 0:
return Rho;
case 1:
return pow(Rho, 2)/2;
case 2:
return pow(Rho, 3)/ 3;
case 3:
return pow(Rho, 4)/ 4;
case 4:
return pow(Rho, 5)/ 5;
case 5:
return (1 - ergho) / double(2 * Gamma);
case 6:
return (1 - ergho * double(Gamma * pow(Rho,2) + double(1)))/ double(2 * Gamma * Gamma);
default:
return 0.0;
}
}
/* H returns a multiplier in each term of the sum
* in P-3
* this is used in conjunction with C in the function Pp
* this represents the product rho^n
* i=0 is the second additive in the formula in reynolds
* i=1 is the third ...
*/
double CarbonDioxide::H(int i, double egrho)
{
if (i < 5) {
return pow(Rho,i+2);
} else if (i == 5) {
return pow(Rho,3)*egrho;
} else if (i == 6) {
return pow(Rho,5)*egrho;
} else {
return 0;
}
}
/*
* internal energy
* see Reynolds eqn (15) section 2
* u = (the integral from T to To of co(T)dT) +
* sum from i to N ([C(i) - T*Cprime(i)] + uo
*/
double CarbonDioxide::up()
{
double Tinverse = 1.0/T;
double T2inverse = pow(T, -2);
double T3inverse = pow(T, -3);
double T4inverse = pow(T, -4);
double egrho = exp(-Gamma*Rho*Rho);
double sum = 0.0;
// Equation C-6 integrated
sum += G[0]*log(T/To);
int i;
for (i=1; i<=5; i++) {
sum += G[i]*(pow(T,i) - pow(To,i))/double(i);
}
for (i=0; i<=6; i++) {
sum += I(i,egrho, Gamma) *
(C(i, Tinverse, T2inverse, T3inverse, T4inverse) - T*Cprime(i,T2inverse, T3inverse, T4inverse));
}
sum += u0;
return sum + m_energy_offset;
}
/*
* entropy
* see Reynolds eqn (16) section 2
*/
double CarbonDioxide::sp()
{
//double Tinverse = 1.0/T;
double T2inverse = pow(T, -2);
double T3inverse = pow(T, -3);
double T4inverse = pow(T, -4);
double egrho = exp(-Gamma*Rho*Rho);
double sum = 0.0;
for (int i=2; i<=5; i++) {
sum += G[i]*(pow(T,i-1) - pow(To,i-1))/double(i-1);
}
sum += G[1]*log(T/To);
sum -= G[0]*(1.0/To - 1.0/T);
for (int i=0; i<=6; i++) {
sum -= Cprime(i,T2inverse, T3inverse, T4inverse)*I(i,egrho,Gamma);
}
sum += s0 - R*log(Rho);
return sum + m_entropy_offset;
}
/*
* Equation P-3 in Reynolds
* P - rho - T
* returns P (pressure)
*/
double CarbonDioxide::Pp()
{
double Tinverse = pow(T,-1);
double T2inverse = pow(T, -2);
double T3inverse = pow(T, -3);
double T4inverse = pow(T, -4);
double egrho = exp(-Gamma*Rho*Rho);
double P = Rho*R*T;
// when i=0 we are on second sum of equation (where rho^2)
for (int i=0; i<=6; i++) {
P += C(i,Tinverse, T2inverse, T3inverse, T4inverse)*H(i,egrho);
}
return P;
}
/*
* Equation S-2 in Reynolds
* Pressure at Saturation
*/
double CarbonDioxide::Psat()
{
double log, sum=0,P;
if ((T < Tmn) || (T > Tc)) {
std::cout << " error in Psat " << TempError << std::endl;
set_Err(TempError); // Error("CarbonDioxide::Psat",TempError,T);
}
for (int i=1; i<=8; i++) {
sum += F[i-1] * pow((T/Tp -1),double(i-1));
}
log = ((Tc/T)-1)*sum;
P=exp(log)*Pc;
//cout << "Psat is returning " << P << " at T " << T << " and Pc " << Pc << " and Tp " << Tp << endl;
return P;
}
/*
* Equation D2 in Reynolds
* liquid density, of rho_f
*/
double CarbonDioxide::ldens()
{
double xx=1-(T/Tc), sum=0;
if ((T < Tmn) || (T > Tc)) {
std::cout << " error in ldens " << TempError << std::endl;
set_Err(TempError);
}
for (int i=1; i<=6; i++) {
sum+=D[i-1]*pow(xx,double(i-1)/3.0);
}
return sum;
}
/*
* the following functions allow users
* to get the properties of CarbonDioxide
* that are not dependent on the state
*/
double CarbonDioxide::Tcrit()
{
return Tc;
}
double CarbonDioxide::Pcrit()
{
return Pc;
}
double CarbonDioxide::Vcrit()
{
return 1.0/Roc;
}
double CarbonDioxide::Tmin()
{
return Tmn;
}
double CarbonDioxide::Tmax()
{
return Tmx;
}
char* CarbonDioxide::name()
{
return (char*) m_name.c_str() ;
}
char* CarbonDioxide::formula()
{
return (char*) m_formula.c_str();
}
double CarbonDioxide::MolWt()
{
return M;
}
}
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