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Allow gibbs as input to first_partial_deriv; closes #951

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This commit is contained in:
Ian Bell
2016-01-29 10:06:35 -07:00
parent 8eb6ef92b9
commit ea1485bb6f
1 changed files with 105 additions and 0 deletions
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105
src/AbstractState.cpp
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@@ -579,6 +579,22 @@ void get_dT_drho(AbstractState &AS, parameters index, CoolPropDbl &dT, CoolPropD
}
break;
}
case iGmass:
case iGmolar:
{
// dg/dT|rho
double dTau_dT = 1/dT_dtau;
dT = R*AS.T()*(AS.dalpha0_dTau()+AS.dalphar_dTau()+AS.delta()*AS.d2alphar_dDelta_dTau())*dTau_dT + R*(1+AS.alpha0() + AS.alphar() + AS.delta()*AS.dalphar_dDelta());
// dg/drho|T
double dDelta_drho = 1/rhor;
drho = AS.T()*R*(AS.dalpha0_dDelta()+AS.dalphar_dDelta()+AS.delta()*AS.d2alphar_dDelta2() + AS.dalphar_dDelta())*dDelta_drho;
if (index == iGmass){
// dg/drho|T / drhomass/drhomolar where drhomass/drhomolar = mole mass
drho /= AS.molar_mass();
dT /= AS.molar_mass();
}
break;
}
case iTau:
dT = 1/dT_dtau; drho = 0; break;
case iDelta:
@@ -765,6 +781,95 @@ TEST_CASE("Check AbstractState","[AbstractState]")
{
CHECK_NOTHROW(shared_ptr<CoolProp::AbstractState> Water(CoolProp::AbstractState::factory("REFPROP", "Water")));
}
}
TEST_CASE("Check derivatives in first_partial_deriv","[derivs_in_first_partial_deriv]")
{
shared_ptr<CoolProp::AbstractState> Water(CoolProp::AbstractState::factory("HEOS", "Water"));
shared_ptr<CoolProp::AbstractState> WaterplusT(CoolProp::AbstractState::factory("HEOS", "Water"));
shared_ptr<CoolProp::AbstractState> WaterminusT(CoolProp::AbstractState::factory("HEOS", "Water"));
shared_ptr<CoolProp::AbstractState> Waterplusrho(CoolProp::AbstractState::factory("HEOS", "Water"));
shared_ptr<CoolProp::AbstractState> Waterminusrho(CoolProp::AbstractState::factory("HEOS", "Water"));
double dT = 1e-3, drho = 1;
Water->update(CoolProp::PT_INPUTS, 101325, 300);
WaterplusT->update(CoolProp::DmolarT_INPUTS, Water->rhomolar(), 300+dT);
WaterminusT->update(CoolProp::DmolarT_INPUTS, Water->rhomolar(), 300-dT);
Waterplusrho->update(CoolProp::DmolarT_INPUTS, Water->rhomolar()+drho, 300);
Waterminusrho->update(CoolProp::DmolarT_INPUTS, Water->rhomolar()-drho, 300);
// Numerical derivatives
CoolPropDbl dP_dT_num = (WaterplusT->p() - WaterminusT->p())/(2*dT);
CoolPropDbl dP_drho_num = (Waterplusrho->p() - Waterminusrho->p())/(2*drho);
CoolPropDbl dHmolar_dT_num = (WaterplusT->hmolar() - WaterminusT->hmolar())/(2*dT);
CoolPropDbl dHmolar_drho_num = (Waterplusrho->hmolar() - Waterminusrho->hmolar())/(2*drho);
CoolPropDbl dHmass_dT_num = (WaterplusT->hmass() - WaterminusT->hmass())/(2*dT);
CoolPropDbl dHmass_drho_num = (Waterplusrho->hmass() - Waterminusrho->hmass())/(2*drho);
CoolPropDbl dSmolar_dT_num = (WaterplusT->smolar() - WaterminusT->smolar())/(2*dT);
CoolPropDbl dSmolar_drho_num = (Waterplusrho->smolar() - Waterminusrho->smolar())/(2*drho);
CoolPropDbl dSmass_dT_num = (WaterplusT->smass() - WaterminusT->smass())/(2*dT);
CoolPropDbl dSmass_drho_num = (Waterplusrho->smass() - Waterminusrho->smass())/(2*drho);
CoolPropDbl dUmolar_dT_num = (WaterplusT->umolar() - WaterminusT->umolar())/(2*dT);
CoolPropDbl dUmolar_drho_num = (Waterplusrho->umolar() - Waterminusrho->umolar())/(2*drho);
CoolPropDbl dUmass_dT_num = (WaterplusT->umass() - WaterminusT->umass())/(2*dT);
CoolPropDbl dUmass_drho_num = (Waterplusrho->umass() - Waterminusrho->umass())/(2*drho);
CoolPropDbl dGmolar_dT_num = (WaterplusT->gibbsmolar() - WaterminusT->gibbsmolar())/(2*dT);
CoolPropDbl dGmolar_drho_num = (Waterplusrho->gibbsmolar() - Waterminusrho->gibbsmolar())/(2*drho);
CoolPropDbl dGmass_dT_num = (WaterplusT->gibbsmass() - WaterminusT->gibbsmass())/(2*dT);
CoolPropDbl dGmass_drho_num = (Waterplusrho->gibbsmass() - Waterminusrho->gibbsmass())/(2*drho);
// Pressure
CoolPropDbl dP_dT_analyt, dP_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iP, dP_dT_analyt, dP_drho_analyt);
// Enthalpy
CoolPropDbl dHmolar_dT_analyt, dHmolar_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iHmolar, dHmolar_dT_analyt, dHmolar_drho_analyt);
CoolPropDbl dHmass_dT_analyt, dHmass_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iHmass, dHmass_dT_analyt, dHmass_drho_analyt);
// Entropy
CoolPropDbl dSmolar_dT_analyt, dSmolar_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iSmolar, dSmolar_dT_analyt, dSmolar_drho_analyt);
CoolPropDbl dSmass_dT_analyt, dSmass_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iSmass, dSmass_dT_analyt, dSmass_drho_analyt);
// Internal energy
CoolPropDbl dUmolar_dT_analyt, dUmolar_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iUmolar, dUmolar_dT_analyt, dUmolar_drho_analyt);
CoolPropDbl dUmass_dT_analyt, dUmass_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iUmass, dUmass_dT_analyt, dUmass_drho_analyt);
// Gibbs
CoolPropDbl dGmolar_dT_analyt, dGmolar_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iGmolar, dGmolar_dT_analyt, dGmolar_drho_analyt);
CoolPropDbl dGmass_dT_analyt, dGmass_drho_analyt;
CoolProp::get_dT_drho(*Water, CoolProp::iGmass, dGmass_dT_analyt, dGmass_drho_analyt);
double eps = 1e-3;
CHECK( std::abs(dP_dT_analyt/dP_dT_num-1) < eps);
CHECK( std::abs(dP_drho_analyt/dP_drho_num-1) < eps);
CHECK( std::abs(dHmolar_dT_analyt/dHmolar_dT_num-1) < eps);
CHECK( std::abs(dHmolar_drho_analyt/dHmolar_drho_num-1) < eps);
CHECK( std::abs(dHmass_dT_analyt/dHmass_dT_num-1) < eps);
CHECK( std::abs(dHmass_drho_analyt/dHmass_drho_num-1) < eps);
CHECK( std::abs(dSmolar_dT_analyt/dSmolar_dT_num-1) < eps);
CHECK( std::abs(dSmolar_drho_analyt/dSmolar_drho_num-1) < eps);
CHECK( std::abs(dSmass_dT_analyt/dSmass_dT_num-1) < eps);
CHECK( std::abs(dSmass_drho_analyt/dSmass_drho_num-1) < eps);
CHECK( std::abs(dUmolar_dT_analyt/dUmolar_dT_num-1) < eps);
CHECK( std::abs(dUmolar_drho_analyt/dUmolar_drho_num-1) < eps);
CHECK( std::abs(dUmass_dT_analyt/dUmass_dT_num-1) < eps);
CHECK( std::abs(dUmass_drho_analyt/dUmass_drho_num-1) < eps);
CHECK( std::abs(dGmolar_dT_analyt/dGmolar_dT_num-1) < eps);
CHECK( std::abs(dGmolar_drho_analyt/dGmolar_drho_num-1) < eps);
CHECK( std::abs(dGmass_dT_analyt/dGmass_dT_num-1) < eps);
CHECK( std::abs(dGmass_drho_analyt/dGmass_drho_num-1) < eps);
}