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Warning

This documentation is for an old version of Cantera. You can find docs for newer versions here.

"""
Adiabatic flame temperature and equilibrium composition for a fuel/air mixture
as a function of equivalence ratio, including formation of solid carbon.
"""

import cantera as ct
import numpy as np
import sys
import csv

##############################################################################
# Edit these parameters to change the initial temperature, the pressure, and
# the phases in the mixture.

T = 300.0
P = 101325.0

# phases
gas = ct.Solution('gri30.xml')
carbon = ct.Solution('graphite.xml')

# the phases that will be included in the calculation, and their initial moles
mix_phases = [(gas, 1.0), (carbon, 0.0)]

# gaseous fuel species
fuel_species = 'CH4'

# air composition
air_N2_O2_ratio = 3.76

# equivalence ratio range
phi_min = 0.3
phi_max = 3.5
npoints = 50

##############################################################################

mix = ct.Mixture(mix_phases)

# create some arrays to hold the data
phi = np.zeros(npoints)
xeq = np.zeros((mix.n_species,npoints))

# find fuel, nitrogen, and oxygen indices
ifuel = gas.species_index(fuel_species)
io2 = gas.species_index('O2')
in2 = gas.species_index('N2')

if gas.n_atoms(fuel_species,'O') > 0 or gas.n_atoms(fuel_species,'N') > 0:
raise "Error: only hydrocarbon fuels are supported."

stoich_O2 = gas.n_atoms(fuel_species,'C') + 0.25*gas.n_atoms(fuel_species,'H')

for i in range(npoints):
phi[i] = phi_min + (phi_max - phi_min)*i/(npoints - 1)
X = np.zeros(gas.n_species)
X[ifuel] = phi[i]
X[io2] = stoich_O2
X[in2] = stoich_O2*air_N2_O2_ratio

# set the gas state
gas.TPX = T, P, X

# create a mixture of 1 mole of gas, and 0 moles of solid carbon.
mix = ct.Mixture(mix_phases)
mix.T = T
mix.P = P

# equilibrate the mixture adiabatically at constant P
mix.equilibrate('HP', solver='gibbs', max_steps=1000)

xeq[:,i] = mix.species_moles

# write output CSV file for importing into Excel
with open(csv_file, 'w') as outfile:
writer = csv.writer(outfile)
writer.writerow(['phi','T (K)'] + mix.species_names)
for i in range(npoints):