# diffusion_flame.py (Source)

```"""
An opposed-flow ethane/air diffusion flame

Requires: cantera >= 2.5.0, matplotlib >= 2.0
Keywords: combustion, 1D flow, diffusion flame, strained flame, plotting,
saving output
"""

import cantera as ct
import matplotlib.pyplot as plt

# Input parameters
p = ct.one_atm  # pressure
tin_f = 300.0  # fuel inlet temperature
tin_o = 300.0  # oxidizer inlet temperature
mdot_o = 0.72  # kg/m^2/s
mdot_f = 0.24  # kg/m^2/s

comp_o = 'O2:0.21, N2:0.78, AR:0.01'  # air composition
comp_f = 'C2H6:1'  # fuel composition

width = 0.02  # Distance between inlets is 2 cm

loglevel = 1  # amount of diagnostic output (0 to 5)

# Create the gas object used to evaluate all thermodynamic, kinetic, and
# transport properties.
gas = ct.Solution('gri30.yaml')
gas.TP = gas.T, p

# Create an object representing the counterflow flame configuration,
# which consists of a fuel inlet on the left, the flow in the middle,
# and the oxidizer inlet on the right.
f = ct.CounterflowDiffusionFlame(gas, width=width)

# Set the state of the two inlets
f.fuel_inlet.mdot = mdot_f
f.fuel_inlet.X = comp_f
f.fuel_inlet.T = tin_f

f.oxidizer_inlet.mdot = mdot_o
f.oxidizer_inlet.X = comp_o
f.oxidizer_inlet.T = tin_o

# Set the boundary emissivities
f.boundary_emissivities = 0.0, 0.0
# Turn radiation off

f.set_refine_criteria(ratio=4, slope=0.2, curve=0.3, prune=0.04)

# Solve the problem
f.solve(loglevel, auto=True)
f.show_solution()
try:
# save to HDF container file if h5py is installed
f.write_hdf('diffusion_flame.h5', mode='w')
except ImportError:
f.save('diffusion_flame.yaml')

# write the velocity, temperature, and mole fractions to a CSV file
f.write_csv('diffusion_flame.csv', quiet=False)

f.show_stats(0)

# Plot Temperature without radiation
figTemperatureModifiedFlame = plt.figure()
plt.plot(f.flame.grid, f.T, label='Temperature without radiation')
plt.title('Temperature of the flame')
plt.ylim(0,2500)
plt.xlim(0.000, 0.020)

# Turn on radiation and solve again