double HFC134a::ldens()
{
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("HFC134a::ldens",
"Temperature out of range. T = " + fp2str(T));
}
double x1 = T/Tc;
double x2 = 1.0 - x1;
return 518.2 + 884.13*pow(x2,1.0/3.0) + 485.84*pow(x2,2.0/3.0)
+ 193.29*pow(x2,10.0/3.0);
}
double hydrogen::Psat()
{
double x = (1.0 - Tt/T)/(1.0 - Tt/Tc);
double result;
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("hydrogen::Psat",
"Temperature out of range. T = " + fp2str(T));
}
result = Fhydro[0]*x + Fhydro[1]*x*x + Fhydro[2]*x*x*x +
Fhydro[3]*x*pow(1-x, alpha);
return exp(result)*Pt;
}
double oxygen::ldens()
{
double xx=1-T/Tc, sum=0;
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("oxygen::ldens",
"Temperature out of range. T = " + fp2str(T));
}
for (int i=0; i<=5; i++) {
sum+=Doxy[i]*pow(xx,double(i)/3.0);
}
return sum;
}
double HFC134a::Psat()
{
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("HFC134a::Psat",
"Temperature out of range. T = " + fp2str(T));
}
double x1 = T/Tc;
double x2 = 1.0 - x1;
double f = -7.686556*x2 + 2.311791*pow(x2,1.5)
- 2.039554*x2*x2 - 3.583758*pow(x2,4);
return Pc*exp(f/x1);
}
double hydrogen::ldens()
{
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("hydrogen::ldens",
"Temperature out of range. T = " + fp2str(T));
}
double x=1-T/Tc;
double sum;
int i;
for (i=1, sum=0; i<=6; i++) {
sum+=Dhydro[i]*pow(x, 1+double(i-1)/3.0);
}
return sum+Roc+Dhydro[0]*pow(x,alpha1);
}
double water::ldens()
{
double sum=0;
int i;
if ((T < Tmn) || (T >= Tc)) {
throw TPX_Error("water::ldens",
"Temperature out of range. T = " + fp2str(T));
}
for (i=0; i<8; i++) {
sum+=D[i]*pow(1.0 - T/Tc, double(i+1)/3.0);
}
double density = Roc*(1+sum);
return density;
}
double water::Psat()
{
double log, sum=0,P;
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("water::Psat",
"Temperature out of range. T = " + fp2str(T));
}
for (int i=1; i<=8; i++) {
sum += F[i-1]*pow(aww*(T-Tp),double(i-1)); // DGG mod
}
log = (Tc/T-1)*sum;
P=exp(log)*Pc;
return P;
}
double methane::ldens()
{
double result;
double sum;
double w;
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("methane::ldens",
"Temperature out of range. T = " + fp2str(T));
}
w = (Tc - T)/(Tc - Tt);
sum = Dmeth[0]*(1.0 - pow(w, 2.0/3.0)) + Dmeth[1]*(1.0 - pow(w, 4.0/3.0))
+ Dmeth[2]*(1.0 - pow(w, 2));
result = pow(w,alpha1)*exp(sum);
result *= (Rot-Roc);
result += Roc;
return result;
}
double oxygen::Psat()
{
double lnp;
int i;
if ((T < Tmn) || (T > Tc)) {
throw TPX_Error("oxygen::Psat",
"Temperature out of range. T = " + fp2str(T));
}
for (i=0, lnp=0; i<=7; i++) {
if (i==3) {
lnp+=Foxy[i]*pow(Tc-T, alpha);
} else {
lnp+=Foxy[i]*pow(T,i-1);
}
}
lnp+=Foxy[8]*log(T);
return exp(lnp);
}
