def test_compute_derivative(self):
rxn_list = [
Reaction(reactants=[self.C2H6],
products=[self.CH3, self.CH3],
kinetics=Arrhenius(A=(686.375e6, '1/s'),
n=4.40721,
Ea=(7.82799, 'kcal/mol'),
T0=(298.15, 'K'))),
Reaction(reactants=[self.C2H6, self.CH3],
products=[self.C2H5, self.CH4],
kinetics=Arrhenius(A=(46.375 * 6, 'm^3/(mol*s)'),
n=3.40721,
Ea=(6.82799, 'kcal/mol'),
T0=(298.15, 'K'))),
Reaction(reactants=[self.C2H6, self.CH3, self.CH3],
products=[self.C2H5, self.C2H5, self.H2],
kinetics=Arrhenius(A=(146.375 * 6, 'm^6/(mol^2*s)'),
n=2.40721,
Ea=(8.82799, 'kcal/mol'),
T0=(298.15, 'K'))),
]
core_species = [self.CH4, self.CH3, self.C2H6, self.C2H5, self.H2]
edge_species = []
core_reactions = rxn_list
edge_reactions = []
num_core_species = len(core_species)
c0 = {
self.CH4: 0.2,
self.CH3: 0.1,
self.C2H6: 0.35,
self.C2H5: 0.15,
self.H2: 0.2
}
rxn_system0 = LiquidReactor(self.T, c0, 1, termination=[])
rxn_system0.initialize_model(core_species, core_reactions,
edge_species, edge_reactions)
dfdt0 = rxn_system0.residual(0.0, rxn_system0.y,
np.zeros(rxn_system0.y.shape))[0]
solver_dfdk = rxn_system0.compute_rate_derivative()
# print 'Solver d(dy/dt)/dk'
# print solver_dfdk
integration_time = 1e-8
model_settings = ModelSettings(tol_keep_in_edge=0,
tol_move_to_core=1,
tol_interrupt_simulation=0)
simulator_settings = SimulatorSettings()
rxn_system0.termination.append(TerminationTime(
(integration_time, 's')))
rxn_system0.simulate(core_species,
core_reactions, [], [], [], [],
model_settings=model_settings,
simulator_settings=simulator_settings)
y0 = rxn_system0.y
dfdk = np.zeros((num_core_species, len(rxn_list))) # d(dy/dt)/dk
c0 = {
self.CH4: 0.2,
self.CH3: 0.1,
self.C2H6: 0.35,
self.C2H5: 0.15,
self.H2: 0.2
}
for i in range(len(rxn_list)):
k0 = rxn_list[i].get_rate_coefficient(self.T)
rxn_list[i].kinetics.A.value_si = rxn_list[
i].kinetics.A.value_si * (1 + 1e-3)
dk = rxn_list[i].get_rate_coefficient(self.T) - k0
rxn_system = LiquidReactor(self.T, c0, 1, termination=[])
rxn_system.initialize_model(core_species, core_reactions,
edge_species, edge_reactions)
dfdt = rxn_system.residual(0.0, rxn_system.y,
np.zeros(rxn_system.y.shape))[0]
dfdk[:, i] = (dfdt - dfdt0) / dk
rxn_system.termination.append(
TerminationTime((integration_time, 's')))
model_settings = ModelSettings(tol_keep_in_edge=0,
tol_move_to_core=1,
tol_interrupt_simulation=0)
simulator_settings = SimulatorSettings()
rxn_system.simulate(core_species,
core_reactions, [], [], [], [],
model_settings=model_settings,
simulator_settings=simulator_settings)
rxn_list[i].kinetics.A.value_si = rxn_list[
i].kinetics.A.value_si / (1 + 1e-3) # reset A factor
for i in range(num_core_species):
for j in range(len(rxn_list)):
self.assertAlmostEqual(dfdk[i, j],
solver_dfdk[i, j],
delta=abs(1e-3 * dfdk[i, j]))
