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100 lines
3.9 KiB
Plaintext
100 lines
3.9 KiB
Plaintext
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#
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# HACA Mechanism - very rough prototype
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# Reference:
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# (1) M. Frenklach, H. Wang,
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# "Detailed Mechanism and Modeling of Soot Particle Formation"
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# in Soot Formation in Combustion: Mechanisms and Models"
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# J. Bockhorn Ed., Springer Verlag, Heidelberg (1994).
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#
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#
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# HKM Notes -> The elements in the element arrays all have to be equal and
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# in the same order. This is a limitation of cads.
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units(length = 'cm', quantity = 'mol', act_energy = 'kcal/mol')
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#------------- the gas -------------------------------------
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ideal_gas(name = 'gas',
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elements = 'O H C N Ar',
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species = 'gri30: H N2 CH3 CH4 C2H2 H2 OH H2O CO O2',
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initial_state = state(temperature = 1400.0,
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pressure = OneAtm,
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mole_fractions = 'H:0.01, N2:0.8899, H2:0.04, CH4:0.01 C2H2:0.01 \
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OH:0.0001 H2O:0.04 O2:0.001'))
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#------------- bulk soot -------------------------------------
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# Taken from Bensen's book.
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# However, entropy is negative; this is not correct.
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# Group contribution approach needs to be modified. Bensen has a
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# negative value for S here, because the group contribution is usually
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# lumped in with other groups which have positive S contributions.
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# However, for the current mechanism, bulk thermodynamics doesn't
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# matter since all reactions involving bulk growth or etching
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# are irreversible.
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#
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stoichiometric_solid(name = 'soot',
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elements = 'O H C N Ar',
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density = (3.52, 'g/cm3'),
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species = 'CB-CB3')
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species(name = 'CB-CB3',
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atoms = 'C:1',
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thermo = const_cp(t0 = (1000., 'K'),
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h0 = (9.22, 'kcal/mol') ,
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s0 = (-3.02, 'cal/mol/K'),
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cp0 = (5.95, 'cal/mol/K') ))
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#------------- the diamond surface -------------------------------------
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#
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# Site density taken from Frenklach/Wang p. 179.
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#
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ideal_interface(name = 'soot_interface',
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elements = 'O H C N Ar ',
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species = 'Csoot-* Csoot-H',
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reactions = 'all',
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phases = 'gas soot',
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site_density = (3.8E-9, 'mol/cm2'),
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initial_state = state(temperature= 1000.0,
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coverages = 'Csoot-*:0.1, Csoot-H:0.9'))
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# HKM -> Note, thermo from the following source:
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# 'S. J. Harris and D. G. Goodwin, 'Growth on
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# the reconstructed diamond (100) surface, 'J. Phys. Chem. vo. 97,
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# 23-28 (1993). reactions a - t are taken directly from Table II,
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# with thermochemistry from Table IV.
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# -> Thermo needs to be reviewed, as deltaG for reactions are
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# very important.
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#
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species(name = 'Csoot-*',
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atoms = 'H:0 C:1',
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thermo = const_cp(t0 = (1000., 'K'),
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h0 = (51.7, 'kcal/mol'),
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s0 = (19.5, 'cal/mol/K'),
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cp0 = (8.41, 'cal/mol/K') ))
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species(name = 'Csoot-H',
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atoms = 'H:1 C:1',
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thermo = const_cp(t0 = (1000., 'K'),
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h0 = (11.4, 'kcal/mol'),
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s0 = (21.0, 'cal/mol/K'),
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cp0 = (8.41, 'cal/mol/K')) )
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#
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# Forward rate constant taken from Frenklach/Wang:
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surface_reaction( 'Csoot-H + H => Csoot-* + H2', [4.17E13, 0.0, 13.0])
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surface_reaction( 'Csoot-* + H2 => Csoot-H + H', [3.9E12, 0.0, 11.0])
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surface_reaction( 'Csoot-H + OH => Csoot-* + H2O', [1.0E10, 0.734, 1.43])
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surface_reaction( 'Csoot-* + H2O => Csoot-H + OH', [3.68E8, 1.139, 17.1])
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surface_reaction( 'Csoot-* + H => Csoot-H', [2.0E13, 0.0, 0.0])
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surface_reaction( 'Csoot-* + C2H2 => Csoot-H + H + 2 CB-CB3', [8.0E7, 1.56, 3.8])
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surface_reaction( 'Csoot-* + O2 + 2 CB-CB3 => Csoot-* + 2 CO', [2.2E12, 0.00, 7.5])
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#surface_reaction( 'OH + Csoot-H + CB-CB3 => Csoot-* + CO + H2', [3.01577E10, 0.5, 0.0])
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surface_reaction( 'OH + Csoot-H + CB-CB3 => Csoot-* + CO + H2', stick(0.13, 0.0, 0.0))
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