An attempt for applying formulation of the carbon combustion in the stagnation flowfield to some experimental comparisons related to the boundary layer combustion

Abstract

An attempt has been made for conducting experimental comparisons by use of such experimental data in the literature as are seemed to have nothing to do with carbon combustion in the stagnation flowfield. Use has been made of aerothermochemical analyses reported in the literature, with the surface C–O2 and C–CO2 reactions and the gas-phase CO–O2 reaction taken into account, with yielding explicit combustion-rate expressions for the combustion response in the limiting situations, by use of the transfer number in terms of the natural logarithmic term. Experiments chosen here are the carbon combustion in an impinging jet of oxidizer, that at the flat-faced cylinder in airflow, that in the natural convection, and that of a rotating disk. In spite of the experimental situation, seemed to be quite different from that in the stagnation flowfield, fair agreement has been demonstrated, in general, in experimental comparisons, because of appropriate evaluations for similarities that lie behind those. In addition, by virtue of this ascertainment, it has turned out that representative parts of those flow configurations can be specified uniquely by a single parameter, just like that in the stagnation flowfield, called the velocity gradient, with further allowing us fair estimations of the combustion rates at the representative positions in those flows. As for the fair agreement being demonstrated, it suggests that the formulation used here has captured the essential feature of the carbon combustion, even in those flows. Various contributions not only for qualitative/quantitative studies but also for practical applications are further anticipated, by use of the formulation used here, because of the single parameter that can specify the flow configuration.