Numerical studies of heterogeneous reaction in stagnation flows using one-dimensional and two-dimensional Cartesian models

Flow over a thin strip is one of the major experimental configurations in the study of catalytic combustion. 1D laminar stagnation-flow models are generally employed to investigate the catalytic combustion characteristics in this experimental configuration. In this study, a 2D Cartesian model is developed to examine the conditions under which 1D models are applicable. The results show that the 1D model is only appropriate in the experimental configurations with a length-to-width ratio less than 1 to 3 (depending on the flow conditions). The 1D model failed because of the neglecting of transverse diffusive mass transfer (at Re < 30) and of the oversimplified convective mass transfer (at Re > 60). The calculations of the 1D and 2D models are also compared against the OH measurements performed in a typical stagnation-flow reactor with a length-to-width ratio of 16. The results show that the computations of the 2D model are in better agreement with the experimental data.