Local Flame Structure and Combustion Noise of Swirl-Stabilized Combustor Controlled by Secondary Fuel Injection

摘要

Simultaneous measurements of CH and OH radicals by planar laser induced fluorescence have been conducted to clarify the relation between the flame structure and combustion noise characteristics of the swirl-stabilized combustor controlled by secondary fuel injection. The spatial and temporal fluctuation of the high temperature gas in the re-circulation zone is reduced by the secondary fuel injection, which results in the reduction of the combustion noise. The frequency control of the secondary fuel injection also reduces the spatial and temporal fluctuation of the flame fronts in the flame zone (or flame bush). At the relevant control frequency, the flame bush becomes thinner and is confined to narrow space.