faster IonFlow test case

ch4_ion.cti

units(length='cm', time='s', quantity='mol', act_energy='cal/mol')

ideal_gas(name='gas',
          elements='O H C N E',
          species=['''gri30: H2      H       O       O2      OH      H2O     HO2
                     H2O2    C       CH      CH2     CH2(S)  CH3     CH4
                     CO      CO2     HCO     CH2O    CH3O    N2''',
                    'HCO+    H3O+    E'],
          reactions=['gri30: all', 'all'],
          transport='Mix',
          options=['skip_undeclared_species', 'skip_undeclared_third_bodies'],
          initial_state=state(temperature=300.0, pressure=OneAtm))

#-------------------------------------------------------------------------------
# Species data
#-------------------------------------------------------------------------------

species(name = 'HCO+',
    atoms = ' H:1  C:1  O:1  E:-1 ',
    thermo = (
       NASA( [  300.00,  1000.00], [  2.473973600E+00,   8.671559000E-03, 
               -1.003150000E-05,   6.717052700E-09,  -1.787267400E-12,
                9.914660800E+04,   8.175711870E+00] ),
       NASA( [ 1000.00,  5000.00], [  3.741188000E+00,   3.344151700E-03, 
               -1.239712100E-06,   2.118938800E-10,  -1.370415000E-14,
                9.888407800E+04,   2.078613570E+00] )
             ),
        transport=gas_transport(geom='linear',
                                diam=3.59,
                                well_depth=498.0,
                                polar=2.5,
                                rot_relax=0.0),
    note = 'J12/70')

species(name = 'H3O+',
    atoms = ' H:3  O:1  E:-1 ',
    thermo = (
       NASA( [  298.15,  1000.00], [  3.792952700E+00,  -9.108540000E-04, 
                1.163635490E-05,  -1.213648870E-08,   4.261596630E-12,
                7.075124010E+04,   1.471568560E+00] ),
       NASA( [ 1000.00,  6000.00], [  2.496477160E+00,   5.728449200E-03, 
               -1.839532810E-06,   2.735774390E-10,  -1.540939850E-14,
                7.097291130E+04,   7.458507790E+00] )
             ),
        transport=gas_transport(geom='nonlinear',
                                diam=2.605,
                                well_depth=572.4,
                                dipole=1.844,
                                polar=1.5,
                                rot_relax=2.1),
     note = 'TPIS89')

species(name = 'E',
    atoms = ' E:1 ',
    thermo = (
       NASA( [  200.00,  1000.00], [  2.500000000E+00,   0.000000000E+00, 
                0.000000000E+00,   0.000000000E+00,   0.000000000E+00,
               -7.453750000E+02,  -1.172469020E+01] ),
       NASA( [ 1000.00,  6000.00], [  2.500000000E+00,   0.000000000E+00, 
                0.000000000E+00,   0.000000000E+00,   0.000000000E+00,
               -7.453750000E+02,  -1.172469020E+01] )
             ),
        transport=gas_transport(geom='atom',
                                diam=2.05,
                                well_depth=145.0,
                                polar=0.667,
                                rot_relax=0.0),
     note = 'gas L10/92')

#-------------------------------------------------------------------------------
# Reaction data
#-------------------------------------------------------------------------------

reaction('CH + O => HCO+ + E', [2.51E+11, 0.0, 1700])

reaction('HCO+ + H2O => H3O+ + CO', [1.51E+15, 0.0, 0.0])

reaction('H3O+ + E => H2O + H', [2.29E+18, -0.5, 0.0])

reaction('H3O+ + E => OH + H + H', [7.95E+21, -1.4, 0.0])

reaction('H3O+ + E => H2 + OH', [1.25E+19, -0.5, 0.0])

reaction('H3O+ + E =>  O + H2 + H', [6.0E+17, -0.3, 0.0])

ion_flame.py

import cantera as ct
import numpy as np

# Simulation parameters
p = ct.one_atm  # pressure [Pa]
Tin = 300.0  # unburned gas temperature [K]
reactants = 'CH4:0.216, O2:2'  # premixed gas composition
width = 0.03  # m
loglevel = 1  # amount of diagnostic output (0 to 8)

# IdealGasMix object used to compute mixture properties, set to the state of the
# upstream fuel-air mixture
gas = ct.Solution('../methane_ion2.cti')
gas.TPX = Tin, p, reactants

# Set up flame object
f = ct.IonFlame(gas, width=width)
f.set_refine_criteria(ratio=4, slope=0.8, curve=1.0)

# phase one
f.solve(loglevel=loglevel, auto=True)
f.write_csv('ion0.csv', quiet=False)

# phase two
f.flame.set_solvingPhase(2)
f.energy_enabled = False
f.velocity_enabled = False

# Solve with Prager's ambipolar diffusion model
f.solve(loglevel)
f.write_csv('ion1.csv', quiet=False)

f.energy_enabled = True
f.velocity_enabled = True
f.solve(loglevel)
f.write_csv('ion2.csv', quiet=False)

# phase three
f.flame.set_solvingPhase(3)
f.poisson_enabled = True
# Solve with electric force
f.solve(loglevel)
f.write_csv('ion3.csv', quiet=False)

f.save('CH4_adiabatic.xml', 'mix', 'solution with mixture-averaged transport')
print('mixture-averaged flamespeed = {0:7f} m/s'.format(f.u[0]))

# write the velocity, temperature, density, and mole fractions to a CSV file
f.write_csv('CH4_adiabatic.csv', quiet=False)
f.write_electric_csv('CH4_adiabatic_ion.csv', quiet=False)