Applications and evaluation of two-line atomic LIF thermometry in sooting combustion environments

Temperature measurements using planar laser-induced fluorescence (PLIF) are most often associated with experimental challenges. In addition, no PLIF t echnique is generally applicable in all kinds of environment. Especially un der sooting conditions problems are prone to arise, which limits the use of these techniques. In this paper the two-line atomic fluorescence (TLAF) te chnique was investigated in sooting environments. Indium atoms were used as thermometry species and seeded into the combustion region. Data from two-dimensional measurements are often difficult to analyse, beca use of problems with treating noise. A statistical analysis method for corr ection of laser fluctuations was developed to increase the precision of the temperature calculations. The results show that TLAF holds promise for temperature measurements in ri ch combustion, such as diesel engines, where other techniques have proven t o fail. Drawbacks with the TLAF technique are that the probe volume is bias ed towards the post-flame zone and that seeding is required. The statistica l analysis improved the precision considerably and is suitable for evaluati on of other two-dimensional thermometry techniques. This paper also present s a critical review and comparison with alternatives, such as OH and NO the rmometry.