Bulk-scale modelling of a combustion oscillator

Abstract

We have measured T_ign(the ignition temperature) and g_f(the critical velocity gradient for flashback) of methane–oxygen jets of various composition. These measurements have permitted us to construct a macroscopic model for a far-from-equilibrium system known as the ‘flashback oscillator’. This system exhibits a variety of dynamical phenomena, including bistability, simple and complex limit cycle oscillation, and possibly aperiodic oscillation. The model behaviour closely mimics the behaviour of the actual system and suggests that this behaviour is determined by the composition-dependence of T_ign and g_f. The model also explains the curious flame anchoring that occurs in the physical system.