Laser-induced Incandescence of Soot for High Pressure Combustion Diagnostics

Accurate determination of soot emissions from combustion is of interest in both fundamental research and industries that rely on combustion. Laser-induced incandescence of soot particles is a young technique that allows unobtrusive measurements of both soot volume fraction and particulate size. An apparatus utilizing this technique has been brought to function for both atmospheric and high pressure measurements. Proof of concept measurements of an atmospheric ethylene-air laminar diffusion flame at 35, 42, and 47 mm above the burner exit correlate well with literature findings. Profile trends of a methane-air diffusion flame at 10, 20, and 40 atm at 6 mm above the burner are similar to reports in literature and are compared to trends from spectral soot emission measurements. Particle size is found to be roughly proportional to pressure. Discussion on the errors of laser-induced incandescence as well as recommendations for improving the apparatus are herein.MAS