libICEpost.src.thermophysicalModels.specie.thermo.Thermo.janaf7

@author: F. Ramognino <federico.ramognino@polimi.it> Last update: 12/06/2023

Attributes

Tstd

Classes

janaf7

Class for computation of thermophysical properties with NASA (janaf) 7-coefficient polynomials.

Module Contents

libICEpost.src.thermophysicalModels.specie.thermo.Thermo.janaf7.Tstd

class libICEpost.src.thermophysicalModels.specie.thermo.Thermo.janaf7.janaf7(Rgas: float, cpLow: Iterable[float], cpHigh: Iterable[float], Tth: float, Tlow: float, Thigh: float)[source]

Bases: libICEpost.src.thermophysicalModels.specie.thermo.Thermo.Thermo.Thermo

Class for computation of thermophysical properties with NASA (janaf) 7-coefficient polynomials.

cp(T) = sum_{i=0,4} ( a_{i} * T^i ) ha(T) = sum_{i=0,4} ( a_{i}/(i + 1) * T^i )*T + a_{5} s(T) = sum_{i=0,4} ( a_{i}/(i + 1) * T^i ) + a_{5} * ln(T) + a_{6}

Attibutes:

Rgas (float): The mass specific gas constant.
cpLow (Iterable[float]): List of polynomial coefficients to compute cp of the specie in the range of temperature below Tth.
cpHigh (Iterable[float]): List of polynomial coefficients to compute cp of the specie in the range of temperature above Tth.
Tth (float): Threshold temperature to change polynomial coefficient to be used to compute the cp of the specie.
Tlow (float): Lower limit of the range of validity of the polynomial coefficients for computation of cp.
Thigh (float): Higher limit of the range of validity of the polynomial coefficients for computation of cp.

__WARNING__: bool = True: If True, a warning is displayed when the temperature is outside of the range of validity.

numCoeffs: int = 7: Number of coefficients

_cpLow: list[float]: Low-temperature coefficients

_cpHigh: list[float]: High-temperature coefficients

_Tlow: float: Lower-limit of validity

_Thigh: float: Higher-limit of validity

_Tth: float: Threshold temperature for changing between low-T and high-T coefficients

property cpLow: list[float]: Low-temperature coefficients

property cpHigh: list[float]: High-temperature coefficients

property Tlow: float: Lower-limit of validity

property Thigh: float: Higher-limit of validity

property Tth: float: Threshold temperature for changing between low-T and high-T coefficients

copy()[source]

Create a copy with the same coefficients.

Returns:: The copied object.
Return type:: janaf7

__str__()[source]

__repr__()[source]

coeffs(T: float) → Iterable[float][source]

Get coefficients, depending on temperature range. - If T < Tth, returns cpLow - If T >= Tth, returns cpHigh

Parameters:: T (float) – Temperature [K].
Returns:: The coefficients to be used for the computation of cp.
Return type:: Iterable[float]

cp(p: float, T: float) → float[source]

Constant pressure heat capacity [J/kg/K]. If the temperature is not within Tlow and Thigh, and janaf7.__WARNING__ is True a warning is displayed.

cp(T) = sum_{i=0,4} ( a_{i} * T^i )

ha(p: float, T: float) → float[source]

Absolute enthalpy [J/kg] If the temperature is not within Tlow and Thigh, a warning is displayed.

ha(T) = sum_{i=0,4} ( a_{i}/(i + 1) * T^i )*T + a_{5}

hf() → float[source]

Enthalpy of formation [J/kg]

hf = ha(Tstd)

dcpdT(p: float, T: float) → float[source]

dcp/dT [J/kg/K^2] If the temperature is not within Tlow and Thigh, a warning is displayed.

dcp/dT(T) = sum_{i=1,4}(i * a_{i} * T^(i - 1))

classmethod fromDictionary(dictionary)[source]

Create from dictionary with the following entries:

Rgas (float): The mass specific gas constant.
cpLow (Iterable[float]): List of polynomial coefficients to compute cp of the specie in the range of temperature below Tth.
cpHigh (Iterable[float]): List of polynomial coefficients to compute cp of the specie in the range of temperature above Tth.
Tth (float): Threshold temperature to change polynomial coefficient to be used to compute the cp of the specie.
Tlow (float): Lower limit of the range of validity of the polynomial coefficients for computation of cp.
Thigh (float): Higher limit of the range of validity of the polynomial coefficients for computation of cp.

Parameters:: dictionary (dict) – Dictionary for construction.
Returns:: The constructed object.
Return type:: janaf7