Due to viscous heating spontaneous ignition of a supersonic flow of premixed combustible gases canoccur in boundary layers. This process is studied numerically for a hydrogen-air mixture in the caseof a laminar bounda...Due to viscous heating spontaneous ignition of a supersonic flow of premixed combustible gases canoccur in boundary layers. This process is studied numerically for a hydrogen-air mixture in the caseof a laminar boundary layer over a flat plate. In a previous study the main structure of the reactingflow was given as well as a first mapping of the ignition conditions versus boundary conditions. In thepresent work computations are performed in order to further specify the controlling mechanisms andparameters of such a boundary layer ignition. We emphasize more precisely i) the elementary stepsof the chemical process which effectively control the ignition n) the unusual role played by the equivalence ratio of the mixture iii) the influence of the Soret effect (species transport due to temperaturegradients).展开更多
文摘Due to viscous heating spontaneous ignition of a supersonic flow of premixed combustible gases canoccur in boundary layers. This process is studied numerically for a hydrogen-air mixture in the caseof a laminar boundary layer over a flat plate. In a previous study the main structure of the reactingflow was given as well as a first mapping of the ignition conditions versus boundary conditions. In thepresent work computations are performed in order to further specify the controlling mechanisms andparameters of such a boundary layer ignition. We emphasize more precisely i) the elementary stepsof the chemical process which effectively control the ignition n) the unusual role played by the equivalence ratio of the mixture iii) the influence of the Soret effect (species transport due to temperaturegradients).
