A model of elementary chemistry and fluid mechanics in the combustion of hydrogen on platinum surfaces

Abstract

Using computational methods, we consider the catalyzed combustion of lean hydrogenoxygen mixtures in a stagnation flow over a platinum surface and in a flat-plate boundary layer. The analysis includes elementary chemistry in the gas phase as well as on the surface. The stagnation flow is modeled using a similarity transformation that leads to a one-dimensional boundary-value problem, whereas the flat-plate boundary layer is modeled by the use of the boundary-layer assumption. Predictions of each model are compared with experimental measurements of (a) catalytic ignition and combustion of hydrogenoxygen mixtures at low pressure (100 millitorr) and (b) OH concentration profiles in catalytically supported combustion at atmospheric pressure. The article proposes reaction mechanisms and interprets the catalytic behavior in terms of the chemistry models.