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An integrated collection in the area of combustion instability is presented. Lord Rayleigh [1] noted that the generation of thermoacoustic oscillations in combustion systems was dependant on the relative phasing between pressure and heat release oscillations. When the heat release oscillations and pressure oscillations are sufficiently in phase with one another, small amplitude pressure perturbations rapidly grow into large amplitude pressure waves. Various experiments monitotring pressure and heat release in laboratory combustors and industrial burners have confirmed the applicability of this criterion [2]. For the particular case of combustion inside a dump combustor, coherent vorical structures shed from the dump plane have been recognized as a potential source of unsteady heat release [3-6] which could couple with pressure oscillations inside the combustor leading to instability. Excess unburnt fuel trapped inside the vortex core could be ignited when the vortex, convecting away from the dump plane, strikes against the walls of the combustor or impinges on the exit nozzle. This sudden combustion of unburnt fuel leads to the generation of a very well defined heat release oscillation whose periodicity... |