Files
cantera/test/python/test_kinetics.py
2024-02-24 17:29:17 -06:00

1873 lines
74 KiB
Python

import numpy as np
import re
import itertools
import importlib.metadata
import pytest
import cantera as ct
from . import utilities
from .utilities import allow_deprecated
# avoid explicit dependence of cantera on scipy
try:
importlib.metadata.version('scipy')
except importlib.metadata.PackageNotFoundError:
_scipy_sparse = ImportError('Method requires a working scipy installation.')
else:
from scipy import sparse as _scipy_sparse
class TestKinetics(utilities.CanteraTest):
def setUp(self):
self.phase = ct.Solution('h2o2.yaml', transport_model=None)
self.phase.X = [0.1, 1e-4, 1e-5, 0.2, 2e-4, 0.3, 1e-6, 5e-5, 0.4, 0]
self.phase.TP = 800, 2*ct.one_atm
@pytest.mark.usefixtures("allow_deprecated")
def test_counts(self):
self.assertEqual(self.phase.n_reactions, 29)
self.assertEqual(self.phase.n_total_species, 10)
self.assertEqual(self.phase.n_phases, 1)
self.assertEqual(self.phase.reaction_phase_index, 0) # deprecated
def test_is_reversible(self):
for i in range(self.phase.n_reactions):
self.assertTrue(self.phase.reaction(i).reversible)
def test_multiplier(self):
fwd_rates0 = self.phase.forward_rates_of_progress
rev_rates0 = self.phase.reverse_rates_of_progress
self.phase.set_multiplier(2.0, 0)
self.phase.set_multiplier(0.1, 6)
fwd_rates1 = self.phase.forward_rates_of_progress
rev_rates1 = self.phase.reverse_rates_of_progress
self.assertNear(2 * fwd_rates0[0], fwd_rates1[0])
self.assertNear(0.1 * fwd_rates0[6], fwd_rates1[6])
self.assertNear(2 * rev_rates0[0], rev_rates1[0])
self.assertNear(0.1 * rev_rates0[6], rev_rates1[6])
for i in range(self.phase.n_reactions):
if i not in (0,6):
self.assertNear(fwd_rates0[i], fwd_rates1[i])
self.assertNear(rev_rates0[i], rev_rates1[i])
self.phase.set_multiplier(0.5)
fwd_rates2 = self.phase.forward_rates_of_progress
rev_rates2 = self.phase.reverse_rates_of_progress
self.assertArrayNear(0.5 * fwd_rates0, fwd_rates2)
self.assertArrayNear(0.5 * rev_rates0, rev_rates2)
def test_legacy_reaction_rate(self):
ct.use_legacy_rate_constants(True)
fwd_rates_legacy = self.phase.forward_rate_constants
ct.use_legacy_rate_constants(False)
fwd_rates = self.phase.forward_rate_constants
ix_3b = np.array([r.reaction_type == "three-body-Arrhenius" for r in self.phase.reactions()])
ix_other = ix_3b == False
self.assertArrayNear(fwd_rates_legacy[ix_other], fwd_rates[ix_other])
self.assertFalse((fwd_rates_legacy[ix_3b] == fwd_rates[ix_3b]).any())
def test_reaction_type(self):
self.assertIn(self.phase.reaction(0).reaction_type, "three-body-Arrhenius")
self.assertIn(self.phase.reaction(2).reaction_type, "Arrhenius")
self.assertIn(self.phase.reaction(2).rate.type, "Arrhenius")
self.assertEqual(self.phase.reaction(21).reaction_type, "falloff-Troe")
with self.assertRaisesRegex(ct.CanteraError, "outside valid range"):
self.phase.reaction(33).reaction_type
with self.assertRaisesRegex(ct.CanteraError, "outside valid range"):
self.phase.reaction(-2).reaction_type
def test_reaction_equations(self):
self.assertEqual(self.phase.n_reactions,
len(self.phase.reaction_equations()))
r,p = [x.split() for x in self.phase.reaction(18).equation.split('<=>')]
self.assertIn('H', r)
self.assertIn('H2O2', r)
self.assertIn('HO2', p)
self.assertIn('H2', p)
def test_reactants_products(self):
for i in range(self.phase.n_reactions):
R = self.phase.reaction(i).reactant_string
P = self.phase.reaction(i).product_string
self.assertTrue(self.phase.reaction(i).equation.startswith(R))
self.assertTrue(self.phase.reaction(i).equation.endswith(P))
for k in range(self.phase.n_species):
if self.phase.reactant_stoich_coeff(k,i) != 0:
self.assertIn(self.phase.species_name(k), R)
if self.phase.product_stoich_coeff(k,i) != 0:
self.assertIn(self.phase.species_name(k), P)
def test_stoich_coeffs(self):
nu_r = self.phase.reactant_stoich_coeffs
nu_p = self.phase.product_stoich_coeffs
def check_reactant(s, i, value):
k = self.phase.kinetics_species_index(s)
self.assertEqual(self.phase.reactant_stoich_coeff(s,i), value)
self.assertEqual(self.phase.reactant_stoich_coeff(k,i), value)
self.assertEqual(nu_r[k,i], value)
def check_product(s, i, value):
k = self.phase.kinetics_species_index(s)
self.assertEqual(self.phase.product_stoich_coeff(k,i), value)
self.assertEqual(self.phase.product_stoich_coeff(s,i), value)
self.assertEqual(nu_p[k,i], value)
# H + H2O2 <=> HO2 + H2
check_reactant('H', 18, 1)
check_reactant('H2O2', 18, 1)
check_reactant('HO2', 18, 0)
check_reactant('H2', 18, 0)
check_product('H', 18, 0)
check_product('H2O2', 18, 0)
check_product('HO2', 18, 1)
check_product('H2', 18, 1)
# 2 O + M <=> O2 + M
check_reactant('O', 0, 2)
check_reactant('O2', 0, 0)
check_product('O', 0, 0)
check_product('O2', 0, 1)
@utilities.unittest.skipIf(isinstance(_scipy_sparse, ImportError), "scipy is not installed")
def test_stoich_coeffs_sparse(self):
nu_r_dense = self.phase.reactant_stoich_coeffs
nu_p_dense = self.phase.product_stoich_coeffs
ct.use_sparse(True)
nu_r_sparse = self.phase.reactant_stoich_coeffs
nu_p_sparse = self.phase.product_stoich_coeffs
self.assertTrue((nu_r_sparse.toarray() == nu_r_dense).all())
self.assertTrue((nu_p_sparse.toarray() == nu_p_dense).all())
ct.use_sparse(False)
def test_rates_of_progress(self):
self.assertEqual(len(self.phase.net_rates_of_progress),
self.phase.n_reactions)
self.assertArrayNear(self.phase.forward_rates_of_progress - self.phase.reverse_rates_of_progress,
self.phase.net_rates_of_progress)
def test_heat_release(self):
hrr = - self.phase.partial_molar_enthalpies.dot(self.phase.net_production_rates)
self.assertNear(hrr, self.phase.heat_release_rate)
self.assertNear(hrr, sum(self.phase.heat_production_rates))
def test_rate_constants(self):
self.assertEqual(len(self.phase.forward_rate_constants), self.phase.n_reactions)
ix = self.phase.reverse_rate_constants != 0.
self.assertArrayNear(
self.phase.forward_rate_constants[ix] / self.phase.reverse_rate_constants[ix],
self.phase.equilibrium_constants[ix])
def test_species_rates(self):
nu_p = self.phase.product_stoich_coeffs
nu_r = self.phase.reactant_stoich_coeffs
creation = (np.dot(nu_p, self.phase.forward_rates_of_progress) +
np.dot(nu_r, self.phase.reverse_rates_of_progress))
destruction = (np.dot(nu_r, self.phase.forward_rates_of_progress) +
np.dot(nu_p, self.phase.reverse_rates_of_progress))
self.assertArrayNear(self.phase.creation_rates, creation)
self.assertArrayNear(self.phase.destruction_rates, destruction)
self.assertArrayNear(self.phase.net_production_rates,
creation - destruction)
def test_reaction_deltas(self):
self.assertArrayNear(self.phase.delta_enthalpy -
self.phase.delta_entropy * self.phase.T,
self.phase.delta_gibbs)
self.assertArrayNear(self.phase.delta_standard_enthalpy -
self.phase.delta_standard_entropy * self.phase.T,
self.phase.delta_standard_gibbs)
class KineticsFromReactions(utilities.CanteraTest):
"""
Test for Kinetics objects which are constructed directly from Reaction
objects instead of from input files.
"""
def test_idealgas(self):
gas1 = ct.Solution("h2o2.yaml")
S = ct.Species.list_from_file("h2o2.yaml")
R = ct.Reaction.list_from_file("h2o2.yaml", gas1)
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=S, reactions=R)
self.assertEqual(gas1.n_reactions, gas2.n_reactions)
gas1.TPY = 800, 2*ct.one_atm, 'H2:0.3, O2:0.7, OH:2e-4, O:1e-3, H:5e-5'
gas2.TPY = gas1.TPY
self.assertTrue((gas1.reactant_stoich_coeffs ==
gas2.reactant_stoich_coeffs).all())
self.assertTrue((gas1.product_stoich_coeffs ==
gas2.product_stoich_coeffs).all())
self.assertArrayNear(gas1.delta_gibbs,
gas2.delta_gibbs)
self.assertArrayNear(gas1.reverse_rate_constants,
gas2.reverse_rate_constants)
self.assertArrayNear(gas1.net_production_rates,
gas2.net_production_rates)
def test_surface(self):
gas = ct.Solution("ptcombust.yaml", "gas")
surf1 = ct.Interface("ptcombust.yaml", "Pt_surf", [gas])
surf_species = ct.Species.list_from_file("ptcombust.yaml")
reactions = ct.Reaction.list_from_file("ptcombust.yaml", surf1)
surf2 = ct.Interface(thermo='ideal-surface', kinetics='surface',
species=surf_species, reactions=reactions,
adjacent=[gas])
surf1.site_density = surf2.site_density = 5e-9
gas.TP = surf2.TP = surf1.TP = 900, 2*ct.one_atm
surf2.coverages = surf1.coverages
self.assertEqual(surf1.n_reactions, surf2.n_reactions)
for k,i in itertools.product(['PT(S)','H2','OH','OH(S)'],
range(surf1.n_species)):
self.assertEqual(surf1.reactant_stoich_coeff(k,i),
surf2.reactant_stoich_coeff(k,i))
self.assertEqual(surf1.product_stoich_coeff(k,i),
surf2.product_stoich_coeff(k,i))
for i in range(surf1.n_reactions):
r1 = surf1.reaction(i)
r2 = surf2.reaction(i)
self.assertEqual(r1.reactants, r2.reactants)
self.assertEqual(r1.products, r2.products)
self.assertEqual(r1.rate.pre_exponential_factor,
r2.rate.pre_exponential_factor)
self.assertEqual(r1.rate.temperature_exponent,
r2.rate.temperature_exponent)
self.assertNear(r1.rate.activation_energy, r2.rate.activation_energy)
self.assertArrayNear(surf1.delta_enthalpy,
surf2.delta_enthalpy)
self.assertArrayNear(surf1.forward_rate_constants,
surf2.forward_rate_constants)
self.assertArrayNear(surf1.reverse_rate_constants,
surf2.reverse_rate_constants)
rop1 = surf1.net_production_rates
rop2 = surf2.net_production_rates
for k in gas.species_names + surf1.species_names:
k1 = surf1.kinetics_species_index(k)
k2 = surf2.kinetics_species_index(k)
self.assertNear(rop1[k1], rop2[k2])
def test_add_reaction(self):
gas1 = ct.Solution('h2o2.yaml', transport_model=None)
S = ct.Species.list_from_file("h2o2.yaml")
R = ct.Reaction.list_from_file("h2o2.yaml", gas1)
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=S, reactions=R[:5])
gas1.TPY = 800, 2*ct.one_atm, 'H2:0.3, O2:0.7, OH:2e-4, O:1e-3, H:5e-5'
gas2.TPY = gas1.TPY
for r in R[5:]:
gas2.add_reaction(r)
self.assertEqual(gas1.n_reactions, gas2.n_reactions)
self.assertTrue((gas1.reactant_stoich_coeffs ==
gas2.reactant_stoich_coeffs).all())
self.assertTrue((gas1.product_stoich_coeffs ==
gas2.product_stoich_coeffs).all())
self.assertArrayNear(gas1.delta_gibbs,
gas2.delta_gibbs)
self.assertArrayNear(gas1.reverse_rate_constants,
gas2.reverse_rate_constants)
self.assertArrayNear(gas1.net_production_rates,
gas2.net_production_rates)
def test_coverage_dependence_flags(self):
gas = ct.Solution("ptcombust.yaml", "gas")
surf = ct.Interface("ptcombust.yaml", "Pt_surf", [gas])
surf.TP = 900, ct.one_atm
surf.coverages = {"PT(S)":1}
with self.assertRaises(NotImplementedError):
surf.net_rates_of_progress_ddCi
# set skip and try to get jacobian again
surf.derivative_settings = {"skip-coverage-dependence": True}
surf.net_rates_of_progress_ddCi
def test_electrochemistry_flags(self):
# Phases
mech = "lithium_ion_battery.yaml"
anode, cathode, metal, electrolyte = ct.import_phases(
mech, ["anode", "cathode", "electron", "electrolyte"])
anode_int = ct.Interface(mech, "edge_anode_electrolyte", adjacent=[anode, metal, electrolyte])
with self.assertRaises(NotImplementedError):
anode_int.net_rates_of_progress_ddCi
# set skip and try to get jacobian again
anode_int.derivative_settings = {"skip-electrochemistry": True}
anode_int.net_rates_of_progress_ddCi
def test_submechanism(self):
# Simplified samples/python/kinetics/extract_submechanism.py
gri30 = ct.Solution('gri30.yaml', transport_model=None)
h2o2 = ct.Solution('h2o2.yaml', transport_model=None)
reactions_plus = []
reactions = []
dest_species = set(h2o2.species_names)
colliders = dest_species.union([None, "M"])
for R in gri30.reactions():
if not all(S in dest_species for S in R.reactants):
continue
if not all(S in dest_species for S in R.products):
continue
reactions_plus.append(R)
if R.third_body_name not in colliders:
continue
reactions.append(R)
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=h2o2.species(), reactions=reactions_plus)
# there is one third-body reaction with an undeclared third body species
gas.n_reactions < len(reactions_plus)
assert gas.n_species == len(h2o2.species_names)
gas = ct.Solution(thermo='ideal-gas', kinetics='gas', species=h2o2.species(),
reactions=reactions)
assert gas.n_reactions == len(reactions)
assert gas.n_species == len(h2o2.species_names)
yaml_file = self.test_work_path / "reduced.yaml"
gas.write_yaml(yaml_file)
restored = ct.Solution(yaml_file)
assert gas.species_names == restored.species_names
assert gas.reaction_equations() == restored.reaction_equations()
class KineticsRepeatability(utilities.CanteraTest):
"""
Tests to make sure that lazily evaluated of terms in the rate expression
are always updated correctly.
"""
T0 = 1200
T1 = 1300
rho0 = 2.4
rho1 = 3.1
P0 = 1.4e5
P1 = 3.7e6
def setup_gas(self, mech):
gas = ct.Solution(mech)
self.X0 = 1 + np.sin(range(1, gas.n_species+1))
self.X1 = 1 + np.sin(range(2, gas.n_species+2))
return gas
def check_rates_composition(self, mech):
gas = self.setup_gas(mech)
gas.TDX = self.T0, self.rho0, self.X0
w1 = gas.net_production_rates
# change everything to guarantee recomputation of rates
gas.TDX = self.T1, self.rho1, self.X1
w2 = gas.net_production_rates
gas.TDX = self.T0, self.rho0, self.X1
w3 = gas.net_production_rates
# change only composition, and make sure the rates match
gas.TDX = self.T0, self.rho0, self.X0
w4 = gas.net_production_rates
self.assertArrayNear(w1, w4)
def check_rates_temperature1(self, mech):
gas = self.setup_gas(mech)
gas.TDX = self.T0, self.rho0, self.X0
w1 = gas.net_production_rates
# change everything to guarantee recomputation of rates
gas.TDX = self.T1, self.rho1, self.X1
w2 = gas.net_production_rates
gas.TDX = self.T1, self.rho0, self.X0
w3 = gas.net_production_rates
# change only temperature, and make sure the rates match
gas.TDX = self.T0, self.rho0, self.X0
w4 = gas.net_production_rates
self.assertArrayNear(w1, w4)
def check_rates_temperature2(self, mech):
gas = self.setup_gas(mech)
gas.TPX = self.T0, self.P0, self.X0
w1 = gas.net_production_rates
# change everything to guarantee recomputation of rates
gas.TPX = self.T1, self.P1, self.X1
w2 = gas.net_production_rates
gas.TPX = self.T1, self.P0, self.X0
w3 = gas.net_production_rates
# change only temperature, and make sure the rates match
gas.TPX = self.T0, self.P0, self.X0
w4 = gas.net_production_rates
self.assertArrayNear(w1, w4)
def check_rates_pressure(self, mech):
gas = self.setup_gas(mech)
gas.TPX = self.T0, self.P0, self.X0
w1 = gas.net_production_rates
# change everything to guarantee recomputation of rates
gas.TPX = self.T1, self.P1, self.X1
w2 = gas.net_production_rates
gas.TPX = self.T0, self.P1, self.X0
w3 = gas.net_production_rates
# change only pressure, and make sure the rates match
gas.TPX = self.T0, self.P0, self.X0
w4 = gas.net_production_rates
self.assertArrayNear(w1, w4)
def test_gri30_composition(self):
self.check_rates_composition("gri30.yaml")
def test_gri30_temperature(self):
self.check_rates_temperature1("gri30.yaml")
self.check_rates_temperature2("gri30.yaml")
def test_gri30_pressure(self):
self.check_rates_pressure("gri30.yaml")
def test_h2o2_composition(self):
self.check_rates_composition("h2o2.yaml")
def test_h2o2_temperature(self):
self.check_rates_temperature1("h2o2.yaml")
self.check_rates_temperature2("h2o2.yaml")
def test_h2o2_pressure(self):
self.check_rates_pressure("h2o2.yaml")
def test_pdep_composition(self):
self.check_rates_composition('pdep-test.yaml')
def test_pdep_temperature(self):
self.check_rates_temperature1('pdep-test.yaml')
self.check_rates_temperature2('pdep-test.yaml')
def test_pdep_pressure(self):
self.check_rates_pressure('pdep-test.yaml')
def test_modify_thermo(self):
# Make sure that thermo modifications propagate through to Kinetics
# Set a gas state that is near enough to equilibrium that changes in the
# reverse rate always show up in the net rate
gas = self.setup_gas("gri30.yaml")
gas.TPX = self.T0, self.P0, self.X0
gas.equilibrate('TP')
gas.TP = gas.T + 20, None
S = {sp.name: sp for sp in ct.Species.list_from_file("gri30.yaml")}
w1 = gas.net_rates_of_progress
OH = gas.species('OH')
OH.thermo = S['CO2'].thermo
gas.modify_species(gas.species_index('OH'), OH)
w2 = gas.net_rates_of_progress
for i,R in enumerate(gas.reactions()):
if ('OH' in R.reactants or 'OH' in R.products) and R.reversible:
# Rate should be different if reaction involves OH
self.assertNotAlmostEqual(w2[i] / w1[i], 1.0)
else:
# Rate should be the same if reaction does not involve OH
self.assertAlmostEqual(w2[i] / w1[i], 1.0)
def test_pdep_err(self):
err_msg = ("InputFileError thrown by PlogRate::validate:",
"Invalid rate coefficient for reaction 'CH2CHOO <=> CH3O + CO'",
"at P = 32019, T = 500.0",
"at P = 32019, T = 1000.0",
"at P = 1.0132e+05, T = 500.0",
"at P = 1.0132e+05, T = 1000.0")
if not ct.debug_mode_enabled():
err_msg += (
"Invalid rate coefficient for reaction 'CH2CHOO <=> CH3 + CO2'",
"at P = 1.0132e+05, T = 500.0",
"InputFileError thrown by Reaction::checkBalance:",
"The following reaction is unbalanced: H2O2 + OH <=> 2 H2O + HO2"
)
try:
ct.Solution('addReactions_err_test.yaml')
self.fail('CanteraError not raised')
except ct.CanteraError as e:
err_msg_list = str(e).splitlines()
for msg in err_msg:
self.assertIn(msg, err_msg_list)
def test_sticking_coeff_err(self):
err_msg = (r"Sticking coefficient is greater than 1 for reaction 'O2 \+ 2 PT\(S\) => 2 O\(S\)'",
"at T = 200.0",
"at T = 500.0",
"at T = 1000.0",
"at T = 2000.0",
"at T = 5000.0",
"at T = 10000.0",
"Sticking coefficient is greater than 1 for reaction",
"StickingRate::validate:",
)
for err in err_msg:
with pytest.warns(UserWarning, match=err):
gas = ct.Solution("sticking_coeff_check.yaml")
ct.Interface("sticking_coeff_check.yaml", "Pt_surf", [gas])
def check_raises(yaml, err_msg, line):
"""Helper function for InputFileErrors"""
err_msg = [err_msg]
err_msg.append("InputFileError thrown by ")
err_msg.append(f"Error on line {line} of ")
with pytest.raises(ct.CanteraError) as ex:
ct.Solution(yaml=yaml)
msg = str(ex.value)
for err in err_msg:
assert err in msg
class TestUndeclared(utilities.CanteraTest):
_gas_def = """
phases:
- name: gas
species:
- h2o2.yaml/species: [H, O2, H2O, HO2]
thermo: ideal-gas
kinetics: gas
"""
def test_raise_undeclared_species(self):
gas_def = self._gas_def + """
reactions:
- equation: O + H2 <=> H + OH # Reaction 3
rate-constant: {A: 3.87e+04, b: 2.7, Ea: 6260.0}
"""
check_raises(gas_def, "contains undeclared species", line=10)
def test_raise_undeclared_third_bodies(self):
gas_def = self._gas_def + """
reactions:
- equation: H + O2 + AR <=> HO2 + AR # Reaction 10
rate-constant: {A: 7.0e+17, b: -0.8, Ea: 0.0}
"""
check_raises(gas_def, "three-body reaction with undeclared", line=10)
def test_skip_undeclared_third_bodies1(self):
gas_def = self._gas_def + """
reactions:
- h2o2.yaml/reactions: declared-species
skip-undeclared-third-bodies: true
"""
gas = ct.Solution(yaml=gas_def)
self.assertEqual(gas.n_reactions, 3)
def test_skip_undeclared_third_bodies2(self):
gas_def = """
phases:
- name: gas
species:
- h2o2.yaml/species: [H, O2, HO2]
thermo: ideal-gas
skip-undeclared-third-bodies: true
kinetics: gas
reactions:
- h2o2.yaml/reactions: declared-species
"""
gas = ct.Solution(yaml=gas_def)
found = False
for rxn in gas.reactions():
if rxn.equation == "H + O2 + M <=> HO2 + M":
found = True
break
self.assertTrue(found)
def test_skip_undeclared_orders(self):
gas_def = self._gas_def + """
reactions:
- equation: H + O2 => HO2
rate-constant: {A: 1.255943e+13, b: -2.0, Ea: 5000.0 cal/mol}
orders:
H2O: 0.2
nonreactant-orders: true
"""
gas = ct.Solution(yaml=gas_def)
self.assertEqual(gas.n_reactions, 1)
def test_raise_nonreactant_orders(self):
gas_def = self._gas_def + """
reactions:
- equation: H + O2 => HO2
rate-constant: {A: 1.255943e+13, b: -2.0, Ea: 5000.0 cal/mol}
orders:
H2O: 0.2
"""
check_raises(gas_def, "Reaction order specified", line=10)
def test_raise_undeclared_orders(self):
gas_def = self._gas_def + """
reactions:
- equation: H + O2 => HO2
rate-constant: {A: 1.255943e+13, b: -2.0, Ea: 5000.0 cal/mol}
orders:
N2: 0.2
nonreactant-orders: true
"""
check_raises(gas_def, "reaction orders for undeclared", line=13)
def test_skip_undeclared_surf_species(self):
phase_defs = """
phases:
- name: gas
thermo: ideal-gas
species:
- gri30.yaml/species: [H2, H, O, OH, H2O, CO2]
- name: Pt_surf
thermo: ideal-surface
species:
- ptcombust.yaml/species: [PT(S), H(S), H2O(S), OH(S), CO2(S), CH2(S)s,
CH(S), C(S), O(S)]
kinetics: surface
reactions: [ptcombust.yaml/reactions: declared-species]
site-density: 2.7063e-09
"""
gas = ct.Solution(yaml=phase_defs, name="gas")
surf = ct.Interface(yaml=phase_defs, name="Pt_surf", adjacent=[gas])
self.assertEqual(surf.n_reactions, 14)
class TestInvalidInput(utilities.CanteraTest):
_gas_def = """
phases:
- name: gas
thermo: ideal-gas
species: [{h2o2.yaml/species: all}]
kinetics: gas
reactions: all
state: {T: 300.0, P: 1 atm, X: {O2: 0.21, N2: 0.79}}
"""
def test_failing_convert1(self):
# invalid preexponential factor units
gas_def = self._gas_def + """
reactions:
- equation: O + H2 <=> H + OH # Reaction 3
rate-constant: {A: 3.87e+04 cm^6/mol^2/s, b: 2.7, Ea: 6260.0}
"""
check_raises(gas_def, "UnitSystem::convert:", line=12)
def test_failing_convert2(self):
# invalid activation energy units
gas_def = self._gas_def + """
reactions:
- equation: O + H2 <=> H + OH # Reaction 3
rate-constant: {A: 3.87e+04, b: 2.7, Ea: 6260.0 m}
"""
check_raises(gas_def, "UnitSystem::convertActivationEnergy:", line=12)
def test_failing_unconfigured1(self):
# missing reaction rate definition
gas_def = self._gas_def + """
reactions:
- equation: O + H2 <=> H + OH
"""
check_raises(gas_def, "is not configured", line=11)
def test_failing_unconfigured2(self):
# missing reaction rate definition
gas_def = self._gas_def + """
reactions:
- equation: 2 OH (+M) <=> H2O2 (+M)
type: falloff
"""
check_raises(gas_def, "is not configured", line=11)
def test_failing_unconfigured3(self):
# missing reaction rate definition
gas_def = self._gas_def + """
reactions:
- equation: O + H2 <=> H + OH
type: pressure-dependent-Arrhenius
"""
check_raises(gas_def, "is not configured", line=11)
def test_failing_invalid_duplicate(self):
# Make sure that the error we get is for the invalid reaction, not for the
# missing duplicate
gas_def = self._gas_def + """
reactions:
- equation: O + H2 <=> H + OH
rate-constant: {A: 3.87e+04, b: 2.7, Ea: 6260.0}
duplicate: true
- equation: O + H2 <=> H + OH
rate-constant: {A: -3.87e+04, b: 2.7, Ea: 6260.0}
duplicate: true
"""
check_raises(gas_def, "negative pre-exponential factor", line=14)
class TestEmptyKinetics(utilities.CanteraTest):
def test_empty(self):
gas = ct.Solution("air-no-reactions.yaml")
self.assertEqual(gas.n_reactions, 0)
self.assertArrayNear(gas.creation_rates, np.zeros(gas.n_species))
self.assertArrayNear(gas.destruction_rates, np.zeros(gas.n_species))
self.assertArrayNear(gas.net_production_rates, np.zeros(gas.n_species))
class TestReactionPath(utilities.CanteraTest):
@classmethod
def setUpClass(cls):
utilities.CanteraTest.setUpClass()
cls.gas = ct.Solution('gri30.yaml', transport_model=None)
cls.gas.TPX = 1300.0, ct.one_atm, 'CH4:0.4, O2:1, N2:3.76'
r = ct.IdealGasReactor(cls.gas)
net = ct.ReactorNet([r])
T = r.T
while T < 1900:
net.step()
T = r.T
def check_dot(self, diagram, element):
diagram.label_threshold = 0
diagram.threshold = 0
dot = diagram.get_dot()
dot = dot.replace('\n', '')
nodes1 = set()
nodes2 = set()
species = set()
for line in dot.split(';'):
m = re.match(r'(.*)\[(.*)\]', line)
if not m:
continue
A, B = m.groups()
if '->' in A:
# edges
nodes1.update(s.strip() for s in A.split('->'))
else:
# nodes
nodes2.add(A.strip())
spec = re.search('label="(.*?)"', B).group(1)
self.assertNotIn(spec, species)
species.add(spec)
# Make sure that the output was actually parsable and that we
# found some nodes
self.assertTrue(nodes1)
self.assertTrue(species)
# All nodes should be connected to some edge (this does not
# require the graph to be connected)
self.assertEqual(nodes1, nodes2)
# All of the species in the graph should contain the element whose
# flux we're looking at
for spec in species:
self.assertTrue(self.gas.n_atoms(spec, element) > 0)
# return fluxes from the dot file for further tests
return [float(re.search('label *= *"(.*?)"', line).group(1))
for line in dot.split(';')
if line.startswith('s') and 'arrowsize' in line]
def get_fluxes(self, diagram):
directional = {}
net = {}
for line in diagram.get_data().strip().split('\n')[1:]:
s = line.split()
fwd = float(s[2])
rev = float(s[3])
directional[s[0], s[1]] = fwd
directional[s[1], s[0]] = -rev
if fwd + rev > 0:
net[s[0], s[1]] = fwd + rev
else:
net[s[1], s[0]] = - fwd - rev
return directional, net
def test_dot_net_autoscaled(self):
for element in ['N', 'C', 'H', 'O']:
diagram = ct.ReactionPathDiagram(self.gas, element)
dot_fluxes = self.check_dot(diagram, element)
self.assertEqual(max(dot_fluxes), 1.0)
def test_dot_net_unscaled(self):
for element in ['N', 'C', 'H', 'O']:
diagram = ct.ReactionPathDiagram(self.gas, element)
diagram.scale = 1.0
dot_fluxes = sorted(self.check_dot(diagram, element))
_, fluxes = self.get_fluxes(diagram)
fluxes = sorted(fluxes.values())
for i in range(1, 20):
self.assertNear(dot_fluxes[-i], fluxes[-i], 1e-2)
def test_dot_oneway_autoscaled(self):
for element in ['N', 'C', 'H', 'O']:
diagram = ct.ReactionPathDiagram(self.gas, element)
diagram.flow_type = 'OneWayFlow'
dot_fluxes = self.check_dot(diagram, element)
self.assertEqual(max(dot_fluxes), 1.0)
def test_dot_oneway_unscaled(self):
for element in ['N', 'C', 'H', 'O']:
diagram = ct.ReactionPathDiagram(self.gas, element)
diagram.scale = 1.0
diagram.flow_type = 'OneWayFlow'
dot_fluxes = sorted(self.check_dot(diagram, element))
fluxes, _ = self.get_fluxes(diagram)
fluxes = sorted(fluxes.values())
for i in range(1, 20):
self.assertNear(dot_fluxes[-i], fluxes[-i], 1e-2)
def test_fluxes(self):
gas = ct.Solution('h2o2.yaml', transport_model=None)
gas.TPX = 1100, 10*ct.one_atm, 'H:0.1, HO2:0.1, AR:6'
diagram = ct.ReactionPathDiagram(gas, 'H')
ropf = gas.forward_rates_of_progress
ropr = gas.reverse_rates_of_progress
fluxes, _ = self.get_fluxes(diagram)
self.assertNear(fluxes['HO2','H'], ropr[5] + ropr[9], 1e-5)
self.assertNear(fluxes['H', 'H2'], 2*ropf[11] + ropf[16], 1e-5)
self.assertNear(fluxes['H', 'H2O'], ropf[15], 1e-5)
self.assertNear(fluxes['H', 'OH'], ropf[17], 1e-5)
self.assertNear(fluxes['HO2','H2'], ropf[16], 1e-5)
self.assertNear(fluxes['HO2', 'H2O'], ropf[15], 1e-5)
self.assertNear(fluxes['HO2', 'OH'], ropf[17], 1e-5)
self.assertNear(fluxes['HO2', 'H2O2'], 2*ropf[26] + 2*ropf[27], 1e-5)
class TestChemicallyActivated(utilities.CanteraTest):
def test_rate_evaluation(self):
gas = ct.Solution("chemically-activated-reaction.yaml")
P = [2026.5, 202650.0, 10132500.0] # pressure
# forward rate of progress, computed using Chemkin
Rf = [2.851022e-04, 2.775924e+00, 2.481792e+03]
for i in range(len(P)):
gas.TPX = 900.0, P[i], [0.01, 0.01, 0.04, 0.10, 0.84]
self.assertNear(gas.forward_rates_of_progress[0], Rf[i], 2e-5)
class ExplicitForwardOrderTest(utilities.CanteraTest):
def setUp(self):
self.gas = ct.Solution("explicit-forward-order.yaml")
self.gas.TPX = 800, 101325, [0.01, 0.90, 0.02, 0.03, 0.04]
def test_irreversibility(self):
# Reactions are irreversible
Rr = self.gas.reverse_rate_constants
for i in range(3):
self.assertEqual(Rr[i], 0.0)
def test_rateConstants(self):
# species order: [H, AR, R1A, R1B, P1]
C = self.gas.concentrations
Rf = self.gas.forward_rates_of_progress
kf = self.gas.forward_rate_constants
self.assertNear(Rf[0], kf[0] * C[2]**1.5 * C[3]**0.5)
self.assertNear(Rf[1], kf[1] * C[0]**1.0 * C[4]**0.2)
self.assertNear(Rf[2], kf[2] * C[2]**3.0)
def test_ratio1(self):
rop1 = self.gas.forward_rates_of_progress
# Double concentration of H and R1A
self.gas.TPX = None, None, [0.02, 0.87, 0.04, 0.03, 0.04]
rop2 = self.gas.forward_rates_of_progress
ratio = rop2/rop1
self.assertNear(ratio[0], 2**1.5) # order of R1A is 1.5
self.assertNear(ratio[1], 2**1.0) # order of H is 1.0
self.assertNear(ratio[2], 2**3) # order of R1A is 3
def test_ratio2(self):
rop1 = self.gas.forward_rates_of_progress
# Double concentration of P1 and R1B
self.gas.TPX = None, None, [0.01, 0.83, 0.02, 0.06, 0.08]
rop2 = self.gas.forward_rates_of_progress
ratio = rop2/rop1
self.assertNear(ratio[0], 2**0.5) # order of R1B is 0.5
self.assertNear(ratio[1], 2**0.2) # order of P1 is 1.0
self.assertNear(ratio[2], 2**0.0) # order of R1B is 0
class TestSofcKinetics(utilities.CanteraTest):
""" Test based on sofc.py """
_mech = "sofc.yaml"
def test_sofc(self):
mech = self._mech
T = 1073.15 # T in K
P = ct.one_atm
TPB_length_per_area = 1.0e7 # TPB length per unit area [1/m]
def newton_solve(f, xstart, C=0.0):
""" Solve f(x) = C by Newton iteration. """
x0 = xstart
dx = 1.0e-6
n = 0
while True:
n += 1
f0 = f(x0) - C
x0 -= f0/(f(x0 + dx) - C - f0)*dx
if n > 1000:
raise Exception('No convergence in Newton solve')
if abs(f0) < 0.00001:
return x0
# Anode-side phases
gas_a, anode_bulk, oxide_a = ct.import_phases(mech,
['gas', 'metal', 'oxide_bulk',])
anode_surf = ct.Interface(mech, 'metal_surface', [gas_a])
oxide_surf_a = ct.Interface(mech, 'oxide_surface', [gas_a, oxide_a])
tpb_a = ct.Interface(mech, 'tpb', [anode_bulk, anode_surf, oxide_surf_a])
# Cathode-side phases
gas_c, cathode_bulk, oxide_c = ct.import_phases(mech,
['gas', 'metal', 'oxide_bulk'])
cathode_surf = ct.Interface(mech, 'metal_surface', [gas_c])
oxide_surf_c = ct.Interface(mech, 'oxide_surface', [gas_c, oxide_c])
tpb_c = ct.Interface(mech, 'tpb', [cathode_bulk, cathode_surf,
oxide_surf_c])
kElectron_a = tpb_a.kinetics_species_index("electron")
def anode_curr(E):
anode_bulk.electric_potential = E
w = tpb_a.net_production_rates
return ct.faraday * w[kElectron_a] * TPB_length_per_area
kElectron_c = tpb_c.kinetics_species_index("electron")
def cathode_curr(E):
cathode_bulk.electric_potential = E + oxide_c.electric_potential
w = tpb_c.net_production_rates
return -ct.faraday * w[kElectron_c] * TPB_length_per_area
# initialization
gas_a.TPX = T, P, 'H2:0.97, H2O:0.03'
gas_a.equilibrate('TP')
gas_c.TPX = T, P, 'O2:1.0, H2O:0.001'
gas_c.equilibrate('TP')
for p in [anode_bulk, anode_surf, oxide_surf_a, oxide_a, cathode_bulk,
cathode_surf, oxide_surf_c, oxide_c, tpb_a, tpb_c]:
p.TP = T, P
for s in [anode_surf, oxide_surf_a, cathode_surf, oxide_surf_c]:
s.advance_coverages(50.0)
# These values are just a regression test with no theoretical basis
self.assertArrayNear(anode_surf.coverages,
[6.18736878e-01, 3.81123655e-01, 8.6303646e-05,
2.59274203e-06, 5.05700981e-05], 1e-7)
self.assertArrayNear(oxide_surf_a.coverages,
[4.99435780e-02, 9.48927983e-01, 1.12840418e-03,
3.35936530e-08], 1e-7)
self.assertArrayNear(cathode_surf.coverages,
[1.48180380e-07, 7.57234727e-14, 9.99999827e-01,
2.49235513e-08, 4.03296469e-13], 1e-7)
self.assertArrayNear(oxide_surf_c.coverages,
[4.99896947e-02, 9.49804199e-01, 2.06104679e-04,
1.11970271e-09], 1e-7)
Ea0 = newton_solve(anode_curr, xstart=-0.51)
Ec0 = newton_solve(cathode_curr, xstart=0.51)
data = []
# vary the anode overpotential, from cathodic to anodic polarization
for Ea in np.linspace(Ea0 - 0.25, Ea0 + 0.25, 20):
anode_bulk.electric_potential = Ea
curr = anode_curr(Ea)
delta_V = curr * 5.0e-5 / 2.0
phi_oxide_c = -delta_V
oxide_c.electric_potential = phi_oxide_c
oxide_surf_c.electric_potential = phi_oxide_c
Ec = newton_solve(cathode_curr, xstart=Ec0+0.1, C=curr)
cathode_bulk.electric_potential = phi_oxide_c + Ec
data.append([Ea - Ea0, 0.1*curr, Ec - Ec0, delta_V,
cathode_bulk.electric_potential -
anode_bulk.electric_potential])
self.compare(data, self.test_data_path / "sofc-test.csv", rtol=1e-7)
class TestLithiumIonBatteryKinetics(utilities.CanteraTest):
""" Test based on lithium_ion_battery.py """
_mech = "lithium_ion_battery.yaml"
def test_lithium_ion_battery(self):
mech = self._mech
samples = 11
soc = np.linspace(0., 1., samples) # [-] Input state of charge (0...1)
current = -1 # [A] Externally-applied current, negative for discharge
T = 293 # T in K
P = ct.one_atm
R_electrolyte = 0.0384 # [Ohm] Electrolyte resistance
area_cathode = 1.1167 # [m^2] Cathode total active material surface area
area_anode = 0.7824 # [m^2] Anode total active material surface area
# Calculate mole fractions from SOC
X_Li_anode_0 = 0.01 # [-] anode Li mole fraction at SOC = 0
X_Li_anode_1 = 0.75 # [-] anode Li mole fraction at SOC = 100
X_Li_cathode_0 = 0.99 # [-] cathode Li mole fraction at SOC = 0
X_Li_cathode_1 = 0.49 # [-] cathode Li mole fraction at SOC = 100
X_Li_anode = (X_Li_anode_1 - X_Li_anode_0) * soc + X_Li_anode_0
X_Li_cathode = (X_Li_cathode_0 - X_Li_cathode_1) * (1 - soc) + X_Li_cathode_1
def newton_solve(f, xstart, C=0.0):
""" Solve f(x) = C by Newton iteration. """
x0 = xstart
dx = 1.0e-6
n = 0
while True:
n += 1
f0 = f(x0) - C
x0 -= f0 / (f(x0 + dx) - C - f0) * dx
if n > 1000:
raise Exception('No convergence in Newton solve')
if abs(f0) < 0.00001:
return x0
# Phases
anode, cathode, metal, electrolyte = ct.import_phases(
mech, ["anode", "cathode", "electron", "electrolyte"])
anode_int = ct.Interface(
mech, "edge_anode_electrolyte", adjacent=[anode, metal, electrolyte])
cathode_int = ct.Interface(
mech, "edge_cathode_electrolyte", adjacent=[cathode, metal, electrolyte])
# initialization
for phase in [anode, cathode, metal, electrolyte, anode_int, cathode_int]:
phase.TP = T, P
# This function returns the Cantera calculated anode current
def anode_current(phi_s, phi_l, X_Li_anode):
# Set mole fraction and electrode and electrolyte potential
anode.X = {"Li[anode]": X_Li_anode, "V[anode]": 1 - X_Li_anode}
metal.electric_potential = phi_s
electrolyte.electric_potential = phi_l
# Calculate the current.
return ct.faraday * anode_int.net_rates_of_progress[0] * area_anode
# This function returns the Cantera calculated cathode current
def cathode_current(phi_s, phi_l, X_Li_cathode):
# Set mole fraction and electrode and electrolyte potential
cathode.X = {"Li[cathode]": X_Li_cathode, "V[cathode]": 1 - X_Li_cathode}
metal.electric_potential = phi_s
electrolyte.electric_potential = phi_l
# Calculate the current. Should be negative for cell discharge.
return - ct.faraday * cathode_int.net_rates_of_progress[0] * area_cathode
# Calculate cell voltage, separately for each entry of the input vectors
data = []
phi_l_anode = 0
phi_s_cathode = 0
for i in range(samples):
# Calculate anode electrolyte potential
phi_s_anode = 0
phi_l_anode = newton_solve(
lambda E: anode_current(phi_s_anode, E, X_Li_anode[i]),
phi_l_anode, C=current)
# Calculate cathode electrode potential
phi_l_cathode = phi_l_anode + current * R_electrolyte
phi_s_cathode = newton_solve(
lambda E: cathode_current(E, phi_l_cathode, X_Li_cathode[i]),
phi_s_cathode, C=current)
# Calculate cell voltage
data.append(phi_s_cathode - phi_s_anode)
data = np.array(data).ravel()
ref = np.genfromtxt(self.test_data_path / "lithium-ion-battery-test.csv")
assert np.allclose(data, ref, rtol=1e-7)
def test_interface_current(self):
file = "lithium_ion_battery.yaml"
# The 'elde' electrode phase is needed as a source/sink for electrons:
anode = ct.Solution(file, "anode")
elect = ct.Solution(file, "electron")
elyte = ct.Solution(file, "electrolyte")
anode_int = ct.Interface(file, "edge_anode_electrolyte", [anode, elect, elyte])
anode.X = [0.9, 0.1]
elyte.X = [0.4, 0.3, 0.15, 0.15]
anode.electric_potential = 0.
elyte.electric_potential = 3.
phases = [anode_int, anode, elect, elyte]
for p in phases:
net_prod_rates = anode_int.get_net_production_rates(p)
charges = p.charges
method = anode_int.interface_current(p)
manual = sum(net_prod_rates * charges) * ct.faraday
self.assertEqual(method, manual)
class TestDuplicateReactions(utilities.CanteraTest):
infile = 'duplicate-reactions.yaml'
def check(self, name):
with self.assertRaisesRegex(ct.CanteraError, 'duplicate reaction'):
ct.Solution(self.infile, name)
def test_forward_multiple(self):
self.check('A')
def test_opposite_direction1(self):
self.check('B')
def test_opposite_direction2(self):
self.check('C')
def test_opposite_direction3(self):
self.check('D')
def test_opposite_direction4(self):
gas = ct.Solution(self.infile, 'E')
self.assertEqual(gas.n_reactions, 2)
def test_common_efficiencies(self):
self.check('F')
def test_disjoint_efficiencies(self):
gas = ct.Solution(self.infile, 'G')
self.assertEqual(gas.n_reactions, 2)
def test_different_type(self):
gas = ct.Solution(self.infile, 'H')
self.assertEqual(gas.n_reactions, 2)
def test_declared_duplicate(self):
gas = ct.Solution(self.infile, 'I')
self.assertEqual(gas.n_reactions, 2)
def test_unmatched_duplicate(self):
self.check('J')
def test_nonreacting_species(self):
gas = ct.Solution(self.infile, 'K')
self.assertEqual(gas.n_reactions, 3)
class TestReaction(utilities.CanteraTest):
@classmethod
def setUpClass(cls):
utilities.CanteraTest.setUpClass()
cls.gas = ct.Solution('h2o2.yaml', transport_model=None)
cls.gas.X = 'H2:0.1, H2O:0.2, O2:0.7, O:1e-4, OH:1e-5, H:2e-5'
cls.gas.TP = 900, 2*ct.one_atm
cls.species = ct.Species.list_from_file("h2o2.yaml")
def test_from_yaml(self):
r = ct.Reaction.from_yaml(
"{equation: 2 O + M <=> O2 + M,"
" type: three-body,"
" rate-constant: {A: 1.2e+11, b: -1.0, Ea: 0.0},"
" efficiencies: {H2: 2.4, H2O: 15.4, AR: 0.83}}",
self.gas)
assert r.third_body is not None
self.assertEqual(r.reactants['O'], 2)
self.assertEqual(r.products['O2'], 1)
self.assertEqual(r.third_body.efficiencies['H2O'], 15.4)
self.assertEqual(r.rate.temperature_exponent, -1.0)
self.assertIn('O', r)
self.assertIn('O2', r)
self.assertNotIn('H2O', r)
def test_listFromFile(self):
R = ct.Reaction.list_from_file("h2o2.yaml", self.gas)
eq1 = [r.equation for r in R]
eq2 = [r.equation for r in self.gas.reactions()]
self.assertEqual(eq1, eq2)
def test_list_from_yaml(self):
yaml = """
- equation: O + H2 <=> H + OH # Reaction 3
rate-constant: {A: 3.87e+04, b: 2.7, Ea: 6260.0}
- equation: O + HO2 <=> OH + O2 # Reaction 4
rate-constant: {A: 2.0e+13, b: 0.0, Ea: 0.0}
- equation: O + H2O2 <=> OH + HO2 # Reaction 5
rate-constant: {A: 9.63e+06, b: 2.0, Ea: 4000.0}
"""
R = ct.Reaction.list_from_yaml(yaml, self.gas)
self.assertEqual(len(R), 3)
self.assertIn('HO2', R[2].products)
self.assertEqual(R[0].rate.temperature_exponent, 2.7)
def test_input_data_from_file(self):
R = self.gas.reaction(0)
data = R.input_data
self.assertEqual(data['type'], 'three-body')
self.assertEqual(data['efficiencies'],
{'H2': 2.4, 'H2O': 15.4, 'AR': 0.83})
self.assertEqual(data['equation'], R.equation)
def test_input_data_from_scratch(self):
r = ct.Reaction({"O":1, "H2":1}, {"H":1, "OH":1},
ct.ArrheniusRate(3.87e1, 2.7, 2.6e7))
data = r.input_data
self.assertNear(data['rate-constant']['A'], 3.87e1)
self.assertNear(data['rate-constant']['b'], 2.7)
self.assertNear(data['rate-constant']['Ea'], 2.6e7)
terms = data['equation'].split()
self.assertIn('O', terms)
self.assertIn('OH', terms)
def test_elementary(self):
r = ct.Reaction({"O":1, "H2":1}, {"H":1, "OH":1},
ct.ArrheniusRate(3.87e1, 2.7, 6260*1000*4.184))
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=self.species, reactions=[r])
gas2.TPX = self.gas.TPX
self.assertNear(gas2.forward_rate_constants[0],
self.gas.forward_rate_constants[2])
self.assertNear(gas2.net_rates_of_progress[0],
self.gas.net_rates_of_progress[2])
def test_arrhenius_rate(self):
R = self.gas.reaction(2)
self.assertNear(R.rate(self.gas.T), self.gas.forward_rate_constants[2])
def test_negative_A(self):
species = ct.Species.list_from_file("gri30.yaml")
r = ct.Reaction("NH:1, NO:1", "N2O:1, H:1",
ct.ArrheniusRate(-2.16e13, -0.23, 0))
self.assertFalse(r.rate.allow_negative_pre_exponential_factor)
with self.assertRaisesRegex(ct.CanteraError, 'negative pre-exponential'):
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
r.rate.allow_negative_pre_exponential_factor = True
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
def test_negative_A_falloff(self):
species = ct.Species.list_from_file("gri30.yaml")
low_rate = ct.Arrhenius(2.16e13, -0.23, 0)
high_rate = ct.Arrhenius(-8.16e12, -0.5, 0)
with self.assertRaisesRegex(ct.CanteraError, 'pre-exponential'):
ct.LindemannRate(low_rate, high_rate, ())
rate = ct.LindemannRate()
self.assertFalse(rate.allow_negative_pre_exponential_factor)
rate.allow_negative_pre_exponential_factor = True
rate.high_rate = high_rate
# Should still fail because of mixed positive and negative A factors
with self.assertRaisesRegex(ct.CanteraError, 'pre-exponential'):
rate.low_rate = low_rate
rate.low_rate = ct.Arrhenius(-2.16e13, -0.23, 0)
rxn = ct.Reaction("NH:1, NO:1", "N2O:1, H:1", rate)
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[rxn])
self.assertLess(gas.forward_rate_constants, 0)
def test_threebody(self):
tb = ct.ThirdBody(efficiencies={"AR":0.7, "H2":2.0, "H2O":6.0})
r = ct.Reaction({"O":1, "H":1}, {"OH":1},
ct.ArrheniusRate(5e11, -1.0, 0.0), third_body=tb)
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=self.species, reactions=[r])
gas2.TPX = self.gas.TPX
self.assertNear(gas2.forward_rate_constants[0],
self.gas.forward_rate_constants[1])
self.assertNear(gas2.net_rates_of_progress[0],
self.gas.net_rates_of_progress[1])
def test_falloff(self):
high_rate = ct.Arrhenius(7.4e10, -0.37, 0.0)
low_rate = ct.Arrhenius(2.3e12, -0.9, -1700 * 1000 * 4.184)
tb = ct.ThirdBody(efficiencies={"AR":0.7, "H2":2.0, "H2O":6.0})
r = ct.Reaction("OH:2", "H2O2:1",
ct.TroeRate(low_rate, high_rate, [0.7346, 94, 1756, 5182]),
third_body=tb)
self.assertEqual(r.rate.type, "falloff")
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=self.species, reactions=[r])
gas2.TPX = self.gas.TPX
self.assertNear(gas2.forward_rate_constants[0],
self.gas.forward_rate_constants[21])
self.assertNear(gas2.net_rates_of_progress[0],
self.gas.net_rates_of_progress[21])
def test_plog(self):
gas1 = ct.Solution('pdep-test.yaml')
species = ct.Species.list_from_file("pdep-test.yaml")
rate = ct.PlogRate([
(0.01*ct.one_atm, ct.Arrhenius(1.2124e13, -0.5779, 10872.7*4184)),
(1.0*ct.one_atm, ct.Arrhenius(4.9108e28, -4.8507, 24772.8*4184)),
(10.0*ct.one_atm, ct.Arrhenius(1.2866e44, -9.0246, 39796.5*4184)),
(100.0*ct.one_atm, ct.Arrhenius(5.9632e53, -11.529, 52599.6*4184))
])
r = ct.Reaction({"R1A":1, "R1B":1}, {"P1":1, "H":1}, rate)
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
gas2.X = gas1.X = 'R1A:0.3, R1B:0.6, P1:0.1'
for P in [0.001, 0.01, 0.2, 1.0, 1.1, 9.0, 10.0, 99.0, 103.0]:
gas1.TP = gas2.TP = 900, P * ct.one_atm
self.assertNear(gas2.forward_rate_constants[0],
gas1.forward_rate_constants[0])
self.assertNear(gas2.net_rates_of_progress[0],
gas1.net_rates_of_progress[0])
def test_plog_rate(self):
gas1 = ct.Solution('pdep-test.yaml')
gas1.TP = 800, 2*ct.one_atm
for i in range(4):
self.assertNear(gas1.reaction(i).rate(gas1.T, gas1.P),
gas1.forward_rate_constants[i])
def test_plog_invalid_third_body(self):
with self.assertRaisesRegex(ct.CanteraError, "Found superfluous"):
gas = ct.Solution("pdep-test.yaml", "plog-invalid")
def test_chebyshev(self):
gas1 = ct.Solution('pdep-test.yaml')
species = ct.Species.list_from_file("pdep-test.yaml")
rate = ct.ChebyshevRate(
temperature_range=(300.0, 2000.0),
pressure_range=(1000, 10000000),
data=[[ 5.28830e+00, -1.13970e+00, -1.20590e-01, 1.60340e-02],
[ 1.97640e+00, 1.00370e+00, 7.28650e-03, -3.04320e-02],
[ 3.17700e-01, 2.68890e-01, 9.48060e-02, -7.63850e-03],
[-3.12850e-02, -3.94120e-02, 4.43750e-02, 1.44580e-02]])
r = ct.Reaction("R5:1, H:1", "P5A:1, P5B:1", rate)
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
gas2.X = gas1.X = 'R5:0.3, P5A:0.6, H:0.1'
for T,P in itertools.product([300, 500, 1500], [1e4, 4e5, 3e6]):
gas1.TP = gas2.TP = T, P
self.assertNear(gas2.forward_rate_constants[0],
gas1.forward_rate_constants[4])
self.assertNear(gas2.net_rates_of_progress[0],
gas1.net_rates_of_progress[4])
def test_chebyshev_single_P(self):
species = ct.Species.list_from_file("pdep-test.yaml")
rate = ct.ChebyshevRate(
temperature_range=(300.0, 2000.0),
pressure_range=(1000, 10000000),
data=[[ 5.28830e+00],
[ 1.97640e+00],
[ 3.17700e-01],
[-3.12850e-02]])
r = ct.Reaction("R5:1, H:1", "P5A:1, P5B:1", rate)
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
# rate constant should be pressure independent
for T in [300, 500, 1500]:
gas.TP = T, 1e4
k1 = gas.forward_rate_constants[0]
gas.TP = T, 1e6
k2 = gas.forward_rate_constants[0]
self.assertNear(k1, k2)
def test_chebyshev_single_T(self):
species = ct.Species.list_from_file("pdep-test.yaml")
rate = ct.ChebyshevRate(
temperature_range=(300.0, 2000.0),
pressure_range=(1000, 10000000),
data=[[ 5.28830e+00, -1.13970e+00, -1.20590e-01, 1.60340e-02]])
r = ct.Reaction("R5:1, H:1", "P5A:1, P5B:1", rate)
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
# rate constant should be temperature independent
for P in [1e4, 2e5, 8e6]:
gas.TP = 400, P
k1 = gas.forward_rate_constants[0]
gas.TP = 1700, P
k2 = gas.forward_rate_constants[0]
self.assertNear(k1, k2)
def test_chebyshev_rate(self):
gas1 = ct.Solution('pdep-test.yaml')
gas1.TP = 800, 2*ct.one_atm
for i in range(4,6):
self.assertNear(gas1.reaction(i).rate(gas1.T, gas1.P),
gas1.forward_rate_constants[i])
def test_chebyshev_bad_shape_yaml(self):
species = ct.Species.list_from_file("pdep-test.yaml")
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[])
with self.assertRaisesRegex(ct.CanteraError, "Inconsistent"):
r = ct.Reaction.from_yaml('''
equation: R5 + H <=> P5A + P5B
type: Chebyshev
temperature-range: [300.0, 2000.0]
pressure-range: [9.86e-03 atm, 98.6 atm]
data:
- [8.2883, -1.1397, -0.12059, 0.016034]
- [1.9764, 1.0037, 7.2865e-03]
- [0.3177, 0.26889, 0.094806, -7.6385e-03]
- [-0.031285, -0.039412, 0.044375, 0.014458]''', gas)
def test_chebyshev_deprecated_third_body(self):
with self.assertRaisesRegex(ct.CanteraError, "in the reaction equation"):
gas = ct.Solution("pdep-test.yaml", "chebyshev-deprecated")
def test_BlowersMasel(self):
r = ct.Reaction({"O":1, "H2":1}, {"H":1, "OH":1},
ct.BlowersMaselRate(3.87e1, 2.7, 6260*1000*4.184, 1e9*1000*4.184))
gas1 = ct.Solution("blowers-masel.yaml", "gas")
self.assertIsInstance(gas1.reaction(0).rate, ct.BlowersMaselRate)
gas2 = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=gas1.species(), reactions=[r])
gas1.TP = self.gas.TP
gas2.TP = self.gas.TP
gas1.X = 'H2:0.1, H2O:0.2, O2:0.7, O:1e-4, OH:1e-5, H:2e-5'
gas2.X = 'H2:0.1, H2O:0.2, O2:0.7, O:1e-4, OH:1e-5, H:2e-5'
self.assertNear(gas2.forward_rate_constants[0],
gas1.forward_rate_constants[0], rtol=1e-7)
self.assertNear(gas2.net_rates_of_progress[0],
gas1.net_rates_of_progress[0], rtol=1e-7)
def test_negative_A_blowersmasel(self):
species = ct.Solution("blowers-masel.yaml").species()
r = ct.Reaction({'O':1, 'H2':1}, {'H':1, 'OH':1},
ct.BlowersMaselRate(-3.87e1, 2.7, 6260*1000*4.184, 1e9))
self.assertFalse(r.rate.allow_negative_pre_exponential_factor)
with self.assertRaisesRegex(ct.CanteraError, 'negative pre-exponential'):
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
r.rate.allow_negative_pre_exponential_factor = True
gas = ct.Solution(thermo='ideal-gas', kinetics='gas',
species=species, reactions=[r])
def test_Blowers_Masel_change_enthalpy(self):
gas = ct.Solution("blowers-masel.yaml")
r = gas.reaction(0)
E0 = r.rate.activation_energy
w = r.rate.bond_energy
A = r.rate.pre_exponential_factor
b = r.rate.temperature_exponent
vp = 2 * w * (w+E0) / (w - E0)
deltaH = gas.delta_enthalpy[0]
E = ((w + deltaH / 2) * (vp - 2 * w + deltaH) ** 2 /
(vp ** 2 - 4 * w ** 2 + deltaH ** 2))
deltaH_high = 10 * gas.reaction(0).rate.activation_energy
deltaH_low = -20 * gas.reaction(0).rate.activation_energy
index = gas.species_index('OH')
species = gas.species('OH')
gas.reaction(0).rate.delta_enthalpy = deltaH
self.assertNear(gas.reaction(0).rate.delta_enthalpy, deltaH)
self.assertNear(E, gas.reaction(0).rate.activation_energy)
perturbed_coeffs = species.thermo.coeffs.copy()
perturbed_coeffs[6] += deltaH_high / ct.gas_constant
perturbed_coeffs[13] += deltaH_high / ct.gas_constant
species.thermo = ct.NasaPoly2(species.thermo.min_temp, species.thermo.max_temp,
species.thermo.reference_pressure, perturbed_coeffs)
gas.modify_species(index, species)
gas.reaction(0).rate.delta_enthalpy = deltaH_high
self.assertNear(gas.reaction(0).rate.delta_enthalpy, deltaH_high)
self.assertNear(deltaH_high, gas.reaction(0).rate.activation_energy)
self.assertNear(A*gas.T**b*np.exp(-deltaH_high/ct.gas_constant/gas.T), gas.forward_rate_constants[0])
perturbed_coeffs = species.thermo.coeffs.copy()
perturbed_coeffs[6] += deltaH_low / ct.gas_constant
perturbed_coeffs[13] += deltaH_low / ct.gas_constant
species.thermo = ct.NasaPoly2(species.thermo.min_temp, species.thermo.max_temp,
species.thermo.reference_pressure, perturbed_coeffs)
gas.modify_species(index, species)
gas.reaction(0).rate.delta_enthalpy = deltaH_low
self.assertNear(gas.reaction(0).rate.delta_enthalpy, deltaH_low)
self.assertEqual(0, gas.reaction(0).rate.activation_energy)
self.assertNear(A*gas.T**b*np.exp(0/ct.gas_constant/gas.T), gas.forward_rate_constants[0])
def test_interface(self):
surf_species = ct.Species.list_from_file("ptcombust.yaml")
gas = ct.Solution("ptcombust.yaml", "gas")
surf1 = ct.Interface("ptcombust.yaml", "Pt_surf", [gas])
rate = ct.InterfaceArrheniusRate(3.7e20, 0, 67.4e6)
rate.coverage_dependencies = {'H(S)': (0, 0, -6e6)}
self.assertNear(rate.coverage_dependencies["H(S)"]["E"], -6e6)
r1 = ct.Reaction(equation="2 H(S) <=> H2 + 2 PT(S)", rate=rate)
surf2 = ct.Interface(thermo='ideal-surface', species=surf_species,
kinetics='surface', reactions=[r1], adjacent=[gas])
surf2.site_density = surf1.site_density
surf1.coverages = surf2.coverages = 'PT(S):0.7, H(S):0.3'
gas.TP = surf2.TP = surf1.TP
for T in [300, 500, 1500]:
gas.TP = surf1.TP = surf2.TP = T, 5*ct.one_atm
self.assertNear(surf1.forward_rate_constants[1],
surf2.forward_rate_constants[0])
self.assertNear(surf1.net_rates_of_progress[1],
surf2.net_rates_of_progress[0])
def test_BlowersMaselinterface(self):
gas = ct.Solution("gri30.yaml", transport_model=None)
gas.TPX = 300, ct.one_atm, {"CH4": 0.095, "O2": 0.21, "AR": 0.79}
surf1 = ct.Interface("blowers-masel.yaml", "Pt_surf", [gas])
rate = ct.InterfaceBlowersMaselRate(3.7e20, 0, 67.4e6, 1e9)
rate.coverage_dependencies = {"H(S)": (0, 0, -6e6)}
self.assertNear(rate.coverage_dependencies["H(S)"]["E"], -6e6)
r1 = ct.Reaction("H(S):2", "H2:1, PT(S):2", rate)
surf_species = []
for species in surf1.species():
surf_species.append(species)
surf2 = ct.Interface(thermo='ideal-surface', species=surf_species,
kinetics='surface', reactions=[r1], adjacent=[gas])
surf2.site_density = surf1.site_density
surf1.coverages = surf2.coverages = 'PT(S):0.7, H(S):0.3'
gas.TP = surf2.TP = surf1.TP
for T in [300, 500, 1500]:
gas.TP = surf1.TP = surf2.TP = T, 5*ct.one_atm
self.assertNear(surf1.forward_rate_constants[0],
surf2.forward_rate_constants[0])
self.assertNear(surf1.net_rates_of_progress[0],
surf2.net_rates_of_progress[0])
def test_modify_invalid(self):
# different reaction type
tbr = self.gas.reaction(0)
R2 = ct.Reaction(tbr.reactants, tbr.products, tbr.rate)
with self.assertRaisesRegex(ct.CanteraError, 'types are different'):
self.gas.modify_reaction(0, R2)
# different reactants
R = self.gas.reaction(4)
with self.assertRaisesRegex(ct.CanteraError, 'Reactants are different'):
self.gas.modify_reaction(24, R)
# different products
R = self.gas.reaction(15)
with self.assertRaisesRegex(ct.CanteraError, 'Products are different'):
self.gas.modify_reaction(16, R)
def test_modify_elementary(self):
gas = ct.Solution('h2o2.yaml', transport_model=None)
gas.TPX = self.gas.TPX
R = gas.reaction(2)
A1 = R.rate.pre_exponential_factor
b1 = R.rate.temperature_exponent
Ta1 = R.rate.activation_energy / ct.gas_constant
T = gas.T
self.assertNear(A1*T**b1*np.exp(-Ta1/T), gas.forward_rate_constants[2])
A2 = 1.5 * A1
b2 = b1 + 0.1
Ta2 = Ta1 * 1.2
R.rate = ct.ArrheniusRate(A2, b2, Ta2 * ct.gas_constant)
gas.modify_reaction(2, R)
self.assertNear(A2*T**b2*np.exp(-Ta2/T), gas.forward_rate_constants[2])
def test_modify_third_body(self):
gas = ct.Solution('h2o2.yaml', transport_model=None)
gas.TPX = self.gas.TPX
R = gas.reaction(5)
A1 = R.rate.pre_exponential_factor
b1 = R.rate.temperature_exponent
T = gas.T
kf1 = gas.forward_rate_constants[5]
A2 = 1.7 * A1
b2 = b1 - 0.1
R.rate = ct.ArrheniusRate(A2, b2, 0.0)
gas.modify_reaction(5, R)
kf2 = gas.forward_rate_constants[5]
self.assertNear((A2*T**b2) / (A1*T**b1), kf2/kf1)
def test_modify_falloff(self):
gas = ct.Solution('gri30.yaml', transport_model=None)
gas.TPX = 1100, 3 * ct.one_atm, 'CH4:1.0, O2:0.4, CO2:0.1, H2O:0.05'
r0 = gas.reaction(11)
self.assertEqual(r0.rate.type, "falloff")
# these two reactions happen to have the same third-body efficiencies
r1 = gas.reaction(49)
r2 = gas.reaction(53)
self.assertEqual(r2.rate.type, "falloff")
self.assertEqual(r1.third_body.efficiencies, r2.third_body.efficiencies)
r2.rate = r1.rate
gas.modify_reaction(53, r2)
kf = gas.forward_rate_constants
self.assertNear(kf[49], kf[53])
def test_modify_plog(self):
gas = ct.Solution('pdep-test.yaml')
gas.TPX = 1010, 0.12 * ct.one_atm, 'R1A:0.3, R1B:0.2, H:0.1, R2:0.4'
r0 = gas.reaction(0)
r1 = gas.reaction(1)
r0.rate = ct.PlogRate(r1.rate.rates)
gas.modify_reaction(0, r0)
kf = gas.forward_rate_constants
self.assertNear(kf[0], kf[1])
# Removing the high-pressure rates should have no effect at low P...
r1.rate = ct.PlogRate(rates=r1.rate.rates[:-4])
gas.modify_reaction(1, r1)
self.assertNear(kf[1], gas.forward_rate_constants[1])
# ... but should change the rate at higher pressures
gas.TP = 1010, 12.0 * ct.one_atm
kf = gas.forward_rates_of_progress
self.assertNotAlmostEqual(kf[0], kf[1])
def test_modify_chebyshev(self):
gas = ct.Solution('pdep-test.yaml')
gas.TPX = 1010, 0.34 * ct.one_atm, 'R1A:0.3, R1B:0.2, H:0.1, R2:0.4'
r1 = gas.reaction(4)
r2 = gas.reaction(5)
r1.rate = ct.ChebyshevRate(
r2.rate.temperature_range, r2.rate.pressure_range, r2.rate.data)
# rates should be different before calling 'modify_reaction'
kf = gas.forward_rate_constants
self.assertNotAlmostEqual(kf[4], kf[5])
gas.modify_reaction(4, r1)
kf = gas.forward_rate_constants
self.assertNear(kf[4], kf[5])
def test_modify_BlowersMasel(self):
gas = ct.Solution("blowers-masel.yaml")
gas.X = 'H2:0.1, H2O:0.2, O2:0.7, O:1e-4, OH:1e-5, H:2e-5'
gas.TP = self.gas.TP
R = gas.reaction(0)
delta_enthalpy = gas.delta_enthalpy[0]
A1 = R.rate.pre_exponential_factor
b1 = R.rate.temperature_exponent
R.rate.delta_enthalpy = delta_enthalpy
Ta1 = R.rate.activation_energy / ct.gas_constant
T = gas.T
self.assertNear(A1 * T**b1 * np.exp(-Ta1 / T), gas.forward_rate_constants[0])
# randomly modify the rate parameters of a Blowers-Masel reaction
A2 = 1.5 * A1
b2 = b1 + 0.1
Ta_intrinsic = R.rate.activation_energy * 1.2
w = R.rate.bond_energy * 0.8
R.rate = ct.BlowersMaselRate(A2, b2, Ta_intrinsic, w)
delta_enthalpy = gas.delta_enthalpy[0]
R.rate.delta_enthalpy = delta_enthalpy
Ta2 = R.rate.activation_energy / ct.gas_constant
gas.modify_reaction(0, R)
self.assertNear(A2 * T**b2 * np.exp(-Ta2 / T), gas.forward_rate_constants[0])
def test_modify_interface(self):
gas = ct.Solution("ptcombust.yaml", "gas")
surf = ct.Interface("ptcombust.yaml", "Pt_surf", [gas])
surf.coverages = 'O(S):0.1, PT(S):0.5, H(S):0.4'
gas.TP = surf.TP
R = surf.reaction(1)
R.rate.coverage_dependencies = {'O(S)': (0.0, 0.0, -3e6)}
surf.modify_reaction(1, R)
# Rate constant should now be independent of H(S) coverage, but
# dependent on O(S) coverage
k1 = surf.forward_rate_constants[1]
surf.coverages = 'O(S):0.2, PT(S):0.4, H(S):0.4'
k2 = surf.forward_rate_constants[1]
surf.coverages = 'O(S):0.2, PT(S):0.6, H(S):0.2'
k3 = surf.forward_rate_constants[1]
self.assertNotAlmostEqual(k1, k2)
self.assertNear(k2, k3)
def test_invalid_sticking(self):
yaml = """
equation: OH + Csoot-H + CB-CB3 + CO => Csoot-* + 2 CO + H2
sticking-coefficient: {A: 0.13, b: 0.0, Ea: 0.0}"""
surf = ct.Interface("haca2.yaml", "soot_interface")
rxn = ct.Reaction.from_yaml(yaml, surf)
with pytest.raises(ct.CanteraError, match="non-interface species"):
surf.add_reaction(rxn)
def test_modify_sticking(self):
gas = ct.Solution("ptcombust.yaml", "gas")
surf = ct.Interface("ptcombust.yaml", "Pt_surf", [gas])
surf.coverages = "O(S):0.1, PT(S):0.5, H(S):0.4"
gas.TP = surf.TP
R = surf.reaction(2)
R.rate = ct.StickingArrheniusRate(0.25, 0, 0) # original sticking coefficient = 1.0
k1 = surf.forward_rate_constants[2]
surf.modify_reaction(2, R)
k2 = surf.forward_rate_constants[2]
self.assertNear(k1, 4*k2)
def test_motz_wise(self):
# Motz & Wise off for all reactions
gas1 = ct.Solution("ptcombust.yaml", "gas")
surf1 = ct.Interface("ptcombust.yaml", "Pt_surf", [gas1])
surf1.coverages = 'O(S):0.1, PT(S):0.5, H(S):0.4'
gas1.TP = surf1.TP
# Motz & Wise correction on for some reactions
gas2 = ct.Solution("ptcombust-motzwise.yaml", "gas")
surf2 = ct.Interface("ptcombust-motzwise.yaml", "Pt_surf", [gas2])
surf2.TPY = surf1.TPY
k1 = surf1.forward_rate_constants
k2 = surf2.forward_rate_constants
# M&W toggled on (globally) for reactions 2 and 7
self.assertNear(2.0 * k1[2], k2[2]) # sticking coefficient = 1.0
self.assertNear(1.6 * k1[7], k2[7]) # sticking coefficient = 0.75
# M&W toggled off (locally) for reaction 4
self.assertNear(k1[4], k2[4])
# M&W toggled on (locally) for reaction 9
self.assertNear(2.0 * k1[9], k2[9]) # sticking coefficient = 1.0
def test_modify_BMinterface(self):
gas = ct.Solution("gri30.yaml", transport_model=None)
gas.TPX = 300, ct.one_atm, {"CH4": 0.095, "O2": 0.21, "AR": 0.79}
surf = ct.Interface("blowers-masel.yaml", "Pt_surf", [gas])
surf.coverages = "O(S):0.1, PT(S):0.5, H(S):0.4"
gas.TP = surf.TP
R = surf.reaction(0)
R.rate.coverage_dependencies = {'O(S)': (0.0, 0.0, -3e6)}
surf.modify_reaction(0, R)
# Rate constant should now be independent of H(S) coverage, but
# dependent on O(S) coverage
Ek = surf.reaction(0).rate.coverage_dependencies["O(S)"]["E"]
k1 = surf.forward_rate_constants[0]
O2_theta_k1 = surf.coverages[-1]
surf.coverages = "O(S):0.2, PT(S):0.4, H(S):0.4"
k2 = surf.forward_rate_constants[0]
O2_theta_k2 = surf.coverages[-1]
O2_delta_theta_k = O2_theta_k1 - O2_theta_k2
surf.coverages = "O(S):0.2, PT(S):0.6, H(S):0.2"
k3 = surf.forward_rate_constants[0]
self.assertNear(k1 / k2, np.exp(-O2_delta_theta_k * Ek / ct.gas_constant / surf.T))
self.assertNear(k2, k3)
def test_modify_BMsticking(self):
gas = ct.Solution("gri30.yaml", transport_model=None)
gas.TPX = 300, ct.one_atm, {"CH4": 0.095, "O2": 0.21, "AR": 0.79}
surf = ct.Interface("blowers-masel.yaml", "Pt_surf", [gas])
surf.coverages = "O(S):0.1, PT(S):0.5, H(S):0.4"
gas.TP = surf.TP
R = surf.reaction(1)
R.rate = ct.StickingBlowersMaselRate(0.25, 0, 0, 1000000) # original sticking coefficient = 1.0
k1 = surf.forward_rate_constants[1]
surf.modify_reaction(1, R)
k2 = surf.forward_rate_constants[1]
self.assertNear(k1, 4*k2)
def test_BMmotz_wise(self):
# Motz & Wise off for all reactions
gas1 = ct.Solution("blowers-masel.yaml", "gas", transport_model=None)
gas1.TPX = 300, ct.one_atm, {"CH4": 0.095, "O2": 0.21, "AR": 0.79}
surf1 = ct.Interface("blowers-masel.yaml", "Pt_surf", [gas1])
surf1.coverages = 'O(S):0.1, PT(S):0.5, H(S):0.4'
gas1.TP = surf1.TP
# Motz & Wise correction on for some reactions
gas2 = ct.Solution("blowers-masel.yaml", "gas")
surf2 = ct.Interface("blowers-masel.yaml", "Pt_motz_wise", [gas2])
surf2.TPY = surf1.TPY
k1 = surf1.forward_rate_constants
k2 = surf2.forward_rate_constants
# M&W toggled on (globally) for reactions 1 and 2
self.assertNear(2.0 * k1[1], k2[1]) # sticking coefficient = 1.0
self.assertNear(1.6 * k1[2], k2[2]) # sticking coefficient = 0.75
# M&W toggled off (locally) for reaction 3
self.assertNear(k1[3], k2[3])
# M&W toggled on (locally) for reaction 4
self.assertNear(k1[4], k2[4]) # sticking coefficient = 1.0