Period between oscillatory ignitions

In this study, the relationship between oscillatory heat release and large vortex structure was systematically examined as a function of flow and chemistry scaling. Figure 16.3 shows the experimental setup used for producing vortex flames. A premixed propane-air jet was ignited, and the flame was stabilized at the exit downstream of a sudden-expansion flameholder. A 75-watt compression driver was used to apply controlled disturbance and to produce periodic vortices into a jet flame. The frequency response of actuation was evaluated separately to maintain a similar amplitude of acoustic disturbance at the exit plane. The objectives were to identify the location for active fuel injection in the general case and to establish a scaling criterion. 

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