Soot particles sizing by temporally resolved laser induced incandescence in premixed and spray flames

The quantitative characterization of sooting flames in terms of soot load and total soot surface area continues to be a major challenge in both fundamental investigations and practical applications. The laser-induced incandescence (LII) technique, based on the original work of Eckbreth and Melton, is widely employed for the determination of soot volume fraction. Although instrumentation and interpretation are still under debate, laser-induced incandescence may also be used to derive the particle diameter, profiting from the size-dependent cooling behavior of the laser-heated particles. This effect has been studied in a premixed ethylene/air laminar flame and in a heavy oil spray flame using temporally resolved LII emission in order to attempt to distinguish two classes of carbonaceous particles as soot and cenosphere.