Numerical Study of Propane-Air Combustion Stability in a Diverging Microburner

In this paper, propagation of propane-air premixed flame in a 2D diverging micro channel has been investigated numerically by emphasizing on the role of wall in flame stability. Effect of inlet velocity, wall thermal conductivity, heat loss coefficient and divergence angle on two modes of instability, blowout and extinction, has been studied. Stability maps have been drawn for straight and diverging channel and it has been shown that divergence angle changes stability map pattern and increases critical heat loss coefficient dramatically. In a certain case, heat loss coefficient of a channel with 0.7o divergence angle is about three times larger than the straight one. The variations of flame position with divergence angle and heat loss coefficient have also been presented.