1 A LASER-INDUCED INCANDESCENCE SYSTEM FOR MEASURING SOOT FLUX IN AIRCRAFT ENGINE EXHAUSTS

To address the need for measuring soot flux from aircraft engines, a system employing laser-induced incandescence (LII) has been developed for measuring soot concentration and velocity, with the potential for measuring particle size. * The † instrument ‡ instantaneously§ images* * up† † to a 1-m chord of an exhaust plume with a spatial resolution of 5.1 cm, and is capable of providing measurements of soot concentration down to 5 µg/m3. Quantitative non-intrusive measurements of soot concentration in the exhaust of a full-scale aircraft engine have been demonstrated using this system, and are presented here. The system enables rapid measurements, taking a data point every 0.1 seconds. Results are also presented from laboratory experiments with this system demonstrating velocity measurement and the potential for particle sizing. Measurements using this system should help to improve the monitoring of soot emissions from aircraft engines