Ignition and combustion of diluted hydrogen mixtures in a flow past an array of catalytic wires

In this paper the catalytic combustion of a diluted hydrogen–oxygen mixture past an array of catalytic wires is numerically studied. The governing equations are transformed by using an appropriate boundary-fitted coordinate system. Using a global reaction rate of the catalytic combustion of hydrogen–oxygen mixtures valid for not very lean mixtures, the catalytic ignition and combustion is studied for a stoichiometric mixture. Auto-ignition at room temperatures can be achieved for Peclet numbers below 0.065. At larger Peclet numbers, the energy input needed per unit length of the wire and the critical wire temperature for ignition have been obtained for different values of the Peclet numbers. The conversion efficiency has been obtained for Peclet numbers up to 30.

Acknowledgments

J. L. acknowledges the support of DGAPA-UNAM, for a short-term fellowship to visit the UPM in Spain. Helpful discussions on this work with Prof. F. J. Higuera are appreciated. This work has been supported by the Macroproyecto ‘La Ciudad Universitaria y la Energía’ and the ‘Proyecto Universitario de Nanotecnología Ambiental (PUNTA)’ of the UNAM.