Effect of particle loading on interference in planar laser induced fluorescence thermometry

Abstract

Planar laser-induced fluorescence (PLIF) of toluene has been applied to measure the gas-phase temperature in a particle-laden jet heated to controlled gas temperatures between 20°C ≤T≤ 120°C. This method utilises the dependence on temperature of the spectral emission of toluene vapour when excited at a wavelength of 266 nm. Single-shot, planar imaging of temperature was achieved with a high signal-to-noise ratio from the ratio of the fluorescent emissions at two wavelength bands that are recorded simultaneously with two intensified CCD cameras, after first correcting for spatial variations in camera efficiency. The effects of interference from particles and laser sheet attenuation on the accuracy of the PLIF thermometry method was investigated for 40 μm PMMA particles, with the volume loading varied in the two-way coupling regime. Reliable measurements were achieved into the two-way coupling regime.