RCAIDE.Library.Attributes.Propellants.Alkane_Mixture

Alkane_Mixture

class Alkane_Mixture(*args, **kwarg)

Bases: Propellant

A class representing a binary mixture of alkane fuels with customizable composition.

tag

Identifier for the propellant (defaults to ‘Alkane_Mixture’)

Type:

str

reactant

Oxidizer used for combustion (defaults to ‘O2’)

Type:

str

propellant_1

First alkane component (default: Ethane)

Type:

Propellant

propellant_1_mass_fraction

Mass fraction of first component (defaults to 0.5)

Type:

float

propellant_2

Second alkane component (default: Propane)

Type:

Propellant

propellant_2_mass_fraction

Mass fraction of second component (defaults to 0.5)

Type:

float

density

Mixture density in kg/m³, computed from components

Type:

float

specific_energy

Mixture specific energy in J/kg, computed from components

Type:

float

energy_density

Mixture energy density in J/m³, computed from components

Type:

float

lower_heating_value

Mixture lower heating value in J/kg, computed from components

Type:

float

Notes

This class implements properties for binary alkane fuel mixtures. All mixture properties are computed using mass fraction weighted averages of the component properties, except density which uses a volume-based mixing rule.

Theory

Density mixing rule: .. math:

\rho_{mix} = \left(\frac{X_1}{\rho_1} + \frac{X_2}{\rho_2}\right)^{-1}

Property mixing rule: .. math:

P_{mix} = X_1P_1 + X_2P_2

where:

• X₁, X₂ are mass fractions

• ρ₁, ρ₂ are component densities

• P₁, P₂ are component properties

Definitions

‘Mass Fraction’

The ratio of component mass to total mixture mass

‘Lower Heating Value’

Heat of combustion excluding latent heat of water vapor

compute_mixture_density()

Compute the mixture density using volume-based mixing rule.

Returns:

rho_mix – Mixture density in kg/m³

Return type:

float

Notes

Uses mixing rule for proper volume-based averaging of alkane components.

compute_mixture_specific_energy()

Compute the mixture specific energy using mass fraction weighted average.

Returns:

e_mix – Mixture specific energy in J/kg

Return type:

float

Notes

Linear combination of component specific energies weighted by mass fractions.

compute_mixture_energy_density()

Compute the mixture energy density from specific energy and density.

Returns:

U_mix – Mixture energy density in J/m³

Return type:

float

Notes

Product of mixture specific energy and mixture density.

compute_mixture_lower_heating_value()

Compute the mixture lower heating value using mass fraction weighted average.

Returns:

LHV_mix – Mixture lower heating value in J/kg

Return type:

float

Notes

Linear combination of component lower heating values weighted by mass fractions.

compute_all()

Update all mixture properties based on current composition.

Notes

Recalculates all mixture properties:

• Density

• Specific energy

• Energy density

• Lower heating value

Should be called after changing mixture composition.