modelPerfectGas
Adiabatic process, perfect gas (p*v = R*T, cp = const.)
Extends from ThermofluidStream.Idealized.Processes.AdiabaticThermodynamicModels.BaseClasses.PartialIdealGas (Base class for adiabatic thermodynamic models assuming an ideal gas (p*v = R*T)).
Information
The model calculates the outlet specific enthalpy based on:
- Inlet state
- Outlet pressure
- Isentropic efficiency
The model assumes a perfect gas (p*v = R*T, cp = const.).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| String | name (from PartialIdealGas) | getInstanceName() | |
| Assumptions | |||
| ThermodynamicValueSpecification | gammaSpec (from PartialIdealGas) | ThermofluidStream.Types.ThermodynamicValueSpecification.State | Specifies whether the isentropic exponent is fixed or obtained from the inlet state |
| Medium.IsentropicExponent | gamma_fixed (from PartialIdealGas) | 1.4 | Fixed isentropic exponent |
| ThermodynamicValueSpecification | cpSpec | ThermofluidStream.Types.ThermodynamicValueSpecification.State | Specifies whether the isobaric heat capacity is fixed or obtained from the inlet state |
| Medium.SpecificHeatCapacity | cp_fixed | 1000 | Constant specific heat capacity |
| Warnings | |||
| AssertionLevel | assertionLevel (from PartialIdealGas) | AssertionLevel.warning | Assertion level |
| Real | relTolZ (from PartialIdealGas) | 0.05 | Relative tolerance of compressibility factor at inlet and outlet (tolerance for ideal gas behaviour) |
| Real | relTolGamma (from PartialIdealGas) | 1e-2 | Relative tolerance for isentropic exponent gamma_in, gamma_out |
| Real | relTolCp | 1e-2 | Relative tolerance between specific isobaric heat capacities cp_in, cp_out |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Medium.ThermodynamicState | state_in (from PartialAdiabatic) | Inlet state | |
| Medium.AbsolutePressure | p_out (from PartialAdiabatic) | Outlet pressure | |
| SI.Efficiency | eta_is (from PartialAdiabatic) | Isentropic efficiency | |
| Medium.SpecificEnthalpy | h_out (from PartialAdiabatic) | Outlet specific enthalpy | |
| SI.SpecificEnthalpy | w_t (from PartialAdiabatic) | Specific technical work | |
| SI.SpecificEnthalpy | w_t_is (from PartialAdiabatic) | Specific isentropic technical work | |
| Medium.AbsolutePressure | p_in (from PartialAdiabatic) | Medium.pressure(state_in) | Inlet pressure |
| Medium.MassFraction[Medium.nXi] | Xi_in (from PartialAdiabatic) | Medium.massFraction(state_in) | Inlet mass fractions |
| Medium.Temperature | T_in (from PartialIdealGas) | Medium.temperature(state_in) | Inlet temperature |
| Medium.Temperature | T_out_is (from PartialIdealGas) | Isentropic outlet temperature | |
| Medium.IsentropicExponent | gamma (from PartialIdealGas) | Isentropic exponent | |
| Medium.IsentropicExponent | gamma_in (from PartialIdealGas) | Medium.isentropicExponent(state_in) | Isentropic exponent (inlet) |
| Medium.IsentropicExponent | gamma_out (from PartialIdealGas) | Medium.isentropicExponent(Medium.setState_phX(p_out, h_out, Xi_in)) | Isentropic exponent (outlet) |
| Real | delta_gamma_rel (from PartialIdealGas) | abs(gamma_out - gamma_in)/max(gamma_out, gamma_in) | Relative difference of isentropic exponents gamma_in, gamma_out |
| Real | Z_in (from PartialIdealGas) | Compressibility factor at inlet | |
| Real | Z_out (from PartialIdealGas) | Compressibility factor at outlet | |
| Medium.ThermodynamicState | state_out (from PartialIdealGas) | Medium.setState_phX(p_out, h_out, Xi_in) | Outlet state |
| SI.Density | rho_in (from PartialIdealGas) | Medium.density(state_in) | Inlet density |
| SI.Density | rho_out (from PartialIdealGas) | Medium.density(state_out) | Outlet density |
| SI.MolarMass | M (from PartialIdealGas) | Medium.molarMass(state_in) | Molar mass |
| Real | isInletIdealGas (from PartialIdealGas) | sign(Z_in - 1/(1 + relTolZ))*sign(1 + relTolZ - Z_in) | = 1.0 if Z_in within tolerance, = -1.0 if tolerance is exceeded |
| Real | isOutletIdealGas (from PartialIdealGas) | sign(Z_out - 1/(1 + relTolZ))*sign(1 + relTolZ - Z_out) | = 1.0 if Z_out within tolerance, = -1.0 if tolerance is exceeded |
| Real | isGammaWithinTol (from PartialIdealGas) | sign(relTolGamma - delta_gamma_rel) | = 1.0 if gamma within tolerance, = -1.0 if tolerance is exceeded |
| Medium.Temperature | T_out | Outlet temperature | |
| Medium.SpecificHeatCapacity | cp | Specific isobaric heat capacity | |
| Medium.SpecificHeatCapacity | cp_in | Medium.specificHeatCapacityCp(state_in) | Specific isobaric heat capacity (inlet) |
| Medium.SpecificHeatCapacity | cp_out | Medium.specificHeatCapacityCp(Medium.setState_phX(p_out, h_out, Xi_in)) | Specific isobaric heat capacity (outlet) |
| Real | delta_cp_rel | abs(cp_out - cp_in)/max(cp_out, cp_in) | Relative difference of specific heat capacities cp_in, cp_out |
| Real | isCpWithinTol | sign(relTolCp - delta_cp_rel) | = 1.0 if within tolerance, = -1.0 if tolerance is exceeded |
Revisions
-
2026, by Raphael Gebhart (raphael.gebhart@dlr.de):
Initial version.