Source Coefficients
The rate expression, Rk is determined by the stoichiometry of the system through the formula
(5-7)
where νkj is the stoichiometric matrix and rj is the reaction rate corresponding to reaction j. The reaction rates depend on the order of the reaction and the molar concentration of each species. In compact form, the equation for the jth reaction rate is
where:
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ck is the molar concentration of species k (SI unit: mol/m3)
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kf,j is the rate coefficient for the jth forward reaction (SI unit: 1/s for first order reactions, m3/(mol·s) for second order reactions or m6/(mol2·s) for third order reactions)
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ν'kj is the stoichiometric matrix corresponding to forward reactions, and
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ν''kj is the stoichiometric matrix corresponding to reverse reactions.
The molar concentration of the kth species is computed via:
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The rate coefficients kj depend exponentially on the gas temperature through Arrhenius law
where Aj is the frequency factor for reaction j, β is the temperature exponent and Ej is the activation energy for reaction j.