Combustion of artificial graphite in stagnation flow: Estimation of global kinetic parameters from experimental results

Mass Transfer Related to Heterogeneous Combustion of Solid Carbon in the Forward Stagnation Region - Part 1 - Combustion Rate and Flame Structure

“…Not only the influence due to the appearance of CO-flame on the temperature profile, but also that on the combustion rate is investigated. Measured results are further compared with predicted results (Makino, 1990;Makino & Law, 1990;Makino, et al, 1994).…”

“…The surface temperature when the CO-flame first appears is called the ignition surface-temperature (Makino & Law, 1990), above which the combustion proceeds with the "strong" CO-oxidation. The solid curve is the predicted combustion rate with the surface kinetic parameters (Makino, et al, 1994) to be explained in the next Section, and the global gas-phase kinetic parameters (Howard, et al, 1973). In numerical calculations, use has been made of the formulation, presented in Section 2.…”

“…3(a). In numerical calculations, use has been made of the formulation mentioned in Section 2 and kinetic parameters (Makino, et al, 1994) to be explained in the next Section. When there exists CO-flame, the gas-phase kinetic parameters used are those for the "strong" CO-oxidation; when the CO-oxidation is too weak to establish the CO-flame, those for the "weak" CO-oxidation are used.…”

“…4 are predicted ignition surface-temperature for Da s,O =10 7 and 10 8 , obtained by the ignition criterion described here and the kinetic parameters (Makino, et al, 1994) to be explained, with keeping as many parameters fixed as possible. The density   of the oxidizing gas in the freestream is estimated at T  = 323 K. The surface Damköhler numbers in the experimental conditions are from 210 7 to 210 8 , which are obtained with B s,O = 4.110 6 m/s.…”

“…Furthermore, in the present plot, the combustion behavior in the Frozen mode purely depends on the surface C-O 2 reaction rate; that in the Flame-detached mode depends on the surface C-CO 2 reaction rate. Since the appropriateness of the present method has been demonstrated, estimation of the surface kinetic parameters is conducted with experimental results (Makino, et al, 1994), by use of an approximate relation (Makino, 1990)  …”