Source code for RCAIDE.Library.Attributes.Propellants.Methane
# RCAIDE/Library/Attributes/Propellants/Methane.py
#
# Created: Mar 2024, M. Clarke
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# Imports
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from .Propellant import Propellant
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# Methane Propellant Class
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[docs]
class Methane(Propellant):
"""
A class representing methane (CH4) fuel properties and emissions characteristics
for propulsion applications.
Attributes
----------
tag : str
Identifier for the propellant ('Methane')
reactant : str
Oxidizer used for combustion ('O2')
density : float
Fuel density in kg/m³ (422.6)
specific_energy : float
Specific energy content in J/kg (5.34e7)
energy_density : float
Energy density in J/m³ (2.26e10)
lower_heating_value : float
Lower heating value in J/kg (5.0e7)
use_high_fidelity_kinetics_model : bool
Flag for using detailed chemical kinetics (False)
fuel_surrogate_chemical_properties : dict
Simplified chemical composition {'CH4': 1.0}
fuel_chemical_properties : dict
Detailed chemical composition {'CH4': 1.0}
air_chemical_properties : dict
Air composition for combustion calculations
{'O2': 0.2095, 'N2': 0.7809, 'AR': 0.0096}
global_warming_potential_100 : Data
100-year global warming potentials
- CO2 : float
Carbon dioxide (1)
- H2O : float
Water vapor (0.06)
- SO2 : float
Sulfur dioxide (-226)
- NOx : float
Nitrogen oxides (52)
- Soot : float
Particulate matter (1166)
- Contrails : float
Contrail formation (11)
Notes
-----
Methane is the simplest hydrocarbon fuel and main component of natural gas.
It offers reduced carbon emissions compared to conventional fuels due to its
high hydrogen-to-carbon ratio.
**Definitions**
'Lower Heating Value'
Heat of combustion excluding latent heat of water vapor
'Global Warming Potential'
Relative measure of heat trapped in atmosphere compared to CO2
'Specific Energy'
Energy content per unit mass, higher than conventional jet fuels
**Major Assumptions**
* Properties are for standard temperature and pressure conditions (15C, 1atm)
* Pure methane composition (no higher hydrocarbons)
* Standard atmospheric composition for air
"""
def __defaults__(self):
"""This sets the default values.
Assumptions:
Density at -162C, 1 atm
Source:
"""
self.tag = 'Methane'
self.reactant = 'O2'
self.density = 422.6 # kg/m^3 (15 C, 1 atm)
self.specific_energy = 5.34e7 # J/kg
self.energy_density = 2.26e10 # J/m^3
self.lower_heating_value = 5.0e7 # J/kg
self.stoichiometric_fuel_air_ratio = 0 # [-] Stoichiometric Fuel to Air ratio
self.heat_of_vaporization = 0 # [J/kg] Heat of vaporization at standard conditions
self.temperature = 0 # [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.global_warming_potential_100.CO2 = 1 # CO2e/kg
self.global_warming_potential_100.H2O = 0.06 # 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.Soot = 1166 # CO2e/kg
self.global_warming_potential_100.Contrails = 11 # kg/CO2e/km
