Abstract
The effect of heat loss on the instability of premixed flames is studied by two-dimensional, unsteady calculations of reactive flows. To obtain the relation between the growth rate and the wave number, i.e., the dispersion relation, a sufficiently small disturbance is superimposed on a planar flame. The superimposed disturbance grows exponentially with time, which is consistent with the prediction of linear analyses. To study the unstable behavior of cellular flames, the disturbance with the linearly most unstable wave number, i.e., the critical wave number, is superimposed. The superimposed disturbance evolves, and the cellular-flame front is formed, owing to intrinsic instability. As the heat loss becomes larger, the cell depth increases and the behavior of cellular flames becomes unstable.
