Source code for RCAIDE.Library.Attributes.Propellants.Liquid_Hydrogen
# RCAIDE/Library/Attributes/Liquid_Hydrogen.py
#
#
# Created: Sep 2023, M. Clarke
# Modified:
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# IMPORT
# ----------------------------------------------------------------------------------------------------------------------
import RCAIDE
from .Propellant import Propellant
import os
import numpy as np
from scipy.interpolate import interp1d
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# Liquid Hydrogen
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[docs]
class Liquid_Hydrogen(Propellant):
"""
A class representing liquid hydrogen (LH2) fuel properties for aviation applications.
Attributes
----------
tag : str
Identifier for the propellant ('Liquid_H2')
reactant : str
Oxidizer used for combustion ('O2')
density : float
Fuel density in kg/m³ (59.9)
specific_energy : float
Specific energy content in J/kg (141.86e6)
energy_density : float
Energy density in J/m³ (8491.0e6)
stoichiometric_fuel_to_air : float
Stoichiometric fuel-to-air ratio (0.0291)
temperatures : Data
Critical temperatures
- autoignition : float
Autoignition temperature in K (845.15)
Notes
-----
Liquid hydrogen represents a zero-carbon aviation fuel option with the highest
specific energy of any fuel, but requires cryogenic storage at extremely low
temperatures (-253°C).
**Definitions**
'Specific Energy'
Energy content per unit mass, approximately 3 times higher than kerosene
'Energy Density'
Energy content per unit volume, lower than conventional fuels due to low density
'Stoichiometric Fuel-to-Air Ratio'
Ideal fuel-to-air mass ratio for complete combustion to H2O
**Major Assumptions**
* Properties are for liquid hydrogen
* No consideration of boil-off losses
References
----------
[1] Roberts, K. (2008). ANALYSIS AND DESIGN OF A HYPERSONIC SCRAMJET ENGINE WITH A STARTING MACH NUMBER OF 4.00 (thesis). UTA. University of Texas at Austin. Retrieved December 30, 2024, from https://arc.uta.edu/publications/td_files/Kristen%20Roberts%20MS.pdf.
"""
def __defaults__(self):
"""This sets the default values.
Assumptions:
None
Source:
http://arc.uta.edu/publications/td_files/Kristen%20Roberts%20MS.pdf
"""
self.tag = 'Liquid_H2'
self.reactant = 'O2'
self.density = 70.85 # [kg/m^3]
self.specific_energy = 120e6 # [J/kg] Considering the lower heating value https://ntrs.nasa.gov/api/citations/20020085127/downloads/20020085127.pdf
self.energy_density = 8491.0e6 # [J/m^3]
self.stoichiometric_fuel_to_air = 0.029411
self.temperatures.autoignition = 845.15 # [K]
self.stoichiometric_fuel_air_ratio = 0.029411 # [-] Stoichiometric Fuel to Air ratio
self.heat_of_vaporization = 0 # [J/kg] Heat of vaporization at standard conditions
self.temperature = 20 # [K] Temperature of fuel
self.pressure = 0 # [Pa] Pressure of fuel
self.fuel_surrogate_S1 = {} # [-] Mole fractions of fuel surrogate species
self.kinetic_mechanism = '' # [-] Kinetic mechanism for fuel surrogate species
self.oxidizer = ''
self.emission_indices.Production = 0.0 # kg/kg
self.emission_indices.CO2 = 0.0 # kg/kg
self.emission_indices.CO = 0.0 # kg/kg
self.emission_indices.H2O = 8.21 # kg/kg
self.emission_indices.SO2 = 0.0 # kg/kg
self.emission_indices.NOx = 0.0539 # kg/kg
self.emission_indices.Soot = 0.0 # kg/kg
self.global_warming_potential_100.CO2 = 1 # CO2e/kg
self.global_warming_potential_100.H2O = 0.06 # CO2e/kg
self.global_warming_potential_100.CO = 1 # CO2e/kg
self.global_warming_potential_100.SO2 = -226 # CO2e/kg
self.global_warming_potential_100.NOx = 52 # CO2e/kg
self.global_warming_potential_100.CO = 1 # CO2e/kg
self.global_warming_potential_100.Soot = 1166 # CO2e/kg
self.global_warming_potential_100.Contrails = 11 # kg/CO2e/km
self.materials_properties = self.cryogen_properties()
[docs]
def cryogen_properties(self, T, prop_name):
"""
Return interpolated liquid hydrogen property value at a given temperature.
Parameters
----------
T : float or ndarray
Temperature(s) in Kelvin at which the property is requested.
prop_name : str
Name of the property to retrieve from the hydrogen data file.
Valid keys include:
- "Temperature (K)"
- "Pressure (MPa)"
- "Density (kg/m3)"
- "Volume (m3/kg)"
- "Internal Energy (kJ/kg)"
- "Enthalpy (kJ/kg)"
- "Entropy (J/g*K)"
- "Cv (J/g*K)"
- "Cp (J/g*K)"
- "Sound Spd. (m/s)"
- "Joule-Thomson (K/MPa)"
- "Viscosity (Pa*s)"
- "Therm. Cond. (W/m*K)"
- "Phase"
Returns
-------
prop_value : float or ndarray
Interpolated property value(s) corresponding to the input temperature(s).
Notes
-----
* Property data is loaded from ``H2_properties.res`` using
:func:`load_hydrogen_properties`.
* Linear interpolation is applied between tabulated values.
* Extrapolation outside the data range is not supported (``fill_value=None``).
* Phase information is categorical and may not be suitable for interpolation.
See Also
--------
RCAIDE.Library.Attributes.Propellants.Liquid_Hydrogen.load_hydrogen_properties
"""
data = load_hydrogen_properties()
temps = np.array(data["Temperature (K)"], dtype=float)
props = np.array(data[prop_name], dtype=float)
interp = interp1d(temps, props, kind="linear", fill_value=None)
return interp(T)
[docs]
def load_hydrogen_properties():
"""
Load hydrogen property data from the RES file.
Parameters
----------
None
Returns
-------
hydrogen_data : dict
Raw hydrogen property data loaded from ``H2_properties.res``.
Notes
-----
Assumes hydrogen behaves as an ideal gas for the stored properties.
Source
------
Internal RCAIDE resource file: ``H2_properties.res``
See Also
--------
RCAIDE.load : Function used to load RES files
"""
ospath = os.path.abspath(__file__)
separator = os.path.sep
rel_path = os.path.dirname(ospath) + separator
return RCAIDE.load(rel_path+ 'H2_properties.res')
