High speed OH PLIF applied to multiphase combustion (Review)

Abstract

Multiphase reactive systems can exhibit highly dynamic combustion phenomena that could be better understood by using recently developed high-repetition-rate optical diagnostic and imaging approaches. Here, we present an overview of recent activities using high-speed (5 kHz) OH planar laser-induced fluorescence to visualize and make measurements in several multiphase reactive systems. This technique is used to visualize the dynamically changing OH concentration in the gas phase near the surface of solids, liquids, and gels. In addition to gas-phase OH imaging, condensed phases of various solid propellants, gels, and liquids are found to fluoresce when exposed to the laser radiation centered at 283.2 nm. Simultaneous imaging of condensed phases and gasphase OH radical fluorescence has proven to be particularly useful for various measurements, and several examples are presented.