doublereal WaterPropsIAPWS::coeffThermExp() const
{
doublereal kappa = isothermalCompressibility();
doublereal beta = coeffPresExp();
doublereal dens = delta * Rho_c;
return kappa * dens * Rgas * beta / M_water;
}
int WaterPropsIAPWS::phaseState(bool checkState) const {
if (checkState) {
if (tau <= 1.0) {
iState = WATER_SUPERCRIT;
} else {
doublereal T = T_c / tau;
doublereal rho = delta * Rho_c;
//doublereal psatTable = psat_est(T);
doublereal rhoMidAtm = 0.5 * (1.01E5 * M_water / (8314.472 * 373.15) + 1.0E3);
doublereal rhoMid = Rho_c + (T - T_c) * (Rho_c - rhoMidAtm) / (T_c - 373.15);
int iStateGuess = WATER_LIQUID;
if (rho < rhoMid) {
iStateGuess = WATER_GAS;
}
doublereal kappa = isothermalCompressibility();
if (kappa >= 0.0) {
iState = iStateGuess;
} else {
// When we are here we are between the spinodal curves
doublereal rhoDel = rho * 1.000001;
//setState_TR(T, rhoDel);
doublereal deltaSave = delta;
doublereal deltaDel = rhoDel / Rho_c;
delta = deltaDel;
m_phi->tdpolycalc(tau, deltaDel);
doublereal kappaDel = isothermalCompressibility();
doublereal d2rhodp2 = (rhoDel * kappaDel - rho * kappa) / (rhoDel - rho);
if (d2rhodp2 > 0.0) {
iState = WATER_UNSTABLELIQUID;
} else {
iState = WATER_UNSTABLEGAS;
}
//setState_TR(T, rho);
delta = deltaSave;
m_phi->tdpolycalc(tau, delta);
}
}
}
return iState;
}
/*
* cv_mole():
*
* Molar heat capacity at constant volume of the mixture.
* Units: J/kmol/K.
*
* For single species, we go directory to the
* general Cp - Cv relation
*
* Cp = Cv + alpha**2 * V * T / beta
*
* where
* alpha = volume thermal expansion coefficient
* beta = isothermal compressibility
*/
doublereal SingleSpeciesTP::cv_mole() const {
doublereal cvbar = cp_mole();
doublereal alpha = thermalExpansionCoeff();
doublereal beta = isothermalCompressibility();
doublereal molecW = molecularWeight(0);
doublereal V = molecW/density();
doublereal T = temperature();
if (beta != 0.0) {
cvbar -= alpha * alpha * V * T / beta;
}
return cvbar;
}
doublereal SingleSpeciesTP::cv_mole() const
{
/*
* For single species, we go directory to the general Cp - Cv relation
*
* Cp = Cv + alpha**2 * V * T / beta
*
* where
* alpha = volume thermal expansion coefficient
* beta = isothermal compressibility
*/
doublereal cvbar = cp_mole();
doublereal alpha = thermalExpansionCoeff();
doublereal beta = isothermalCompressibility();
doublereal V = molecularWeight(0)/density();
doublereal T = temperature();
if (beta != 0.0) {
cvbar -= alpha * alpha * V * T / beta;
}
return cvbar;
}
