Diagnosing Gas-Turbine-Like Combustion by Use of PLIF

A report describes experiments in which planar laser-induced fluorescence (PLIF) of hydroxyl radicals was used to study the structures of flames in burner test rigs (a flame-tube combustor and a sector combustor) under conditions like those in combustors of aviation gas-turbine engines. The PLIF images from the sector-combustor experiments generally confirmed that the combustor functioned as designed. The PLIF images from the flame-tube experiments revealed previously unknown nonuniformities in flame structures; these images provided guidance for selection of an optimum number of fuel-injection points and for modifications of the fuel-injector design to improve combustion characteristics.