Effects of the combustor size and the molecular diffusion on a methane air premixed microflame stability

Abstract

In this research work the effects of the cylindrical combustor size and the molecular diffusion on a methane air premixed microflame stability are investigated in order to highlight the parameters that most influence the given stability of the flame during microcombustion. A premixed methaneous–air microflame has been through a simulation-modelisation method was established as in a microreactor with a cylindrical configuration. Variable external diameters have been tested with a fixed thickness e = 200 μm and a length L = 10000 μm. The input dimensions of the micro-reactor considered are 2000 μm, 1000 μm, 500μm, 300μm and 200 μm. The results showed that the molecular diffusion coefficient influences the position, the formation and the shape of the flame along the micro reactor unpreviously. Indeed, when the inlet diameter of the reactants is reduced, the flame is shapely deflected from the inlet of the microreactor towards the inside of the reactor with a more bamboo appearance allowing a certain more or less intensive temperature redistribution along the micro-reactor walls. Nevertheless, the order of magnitude of the temperature does not suffer from any influence because of the stability of the coefficient of the molecular diffusion.