Fig. 5.
Forces that influence the stability of the unstructured regime. The convective Froude number (Frc2) is a metric for the relative influence of inertial forces (velocity of gases within the flame) to buoyant forces (buoyancy of the gases within the flame) on the structure of a flame. The plot shows values of PSU (the probability of structured-to-unstructured transitions) and Frc2 for flames propagating along strips of different widths (closed circle, ●) and temperatures (open square, □). The trend in PSU suggests that the probability of transitions increases as the relative influence of buoyant forces increases (relative to the influence of inertial forces); that is, low-Frc2 conditions stabilize the unstructured regime (relative to the structured regime). Error bars represent SE (n ≥ 25 for PSU, n ≥ 5 for Frc2).