Soot Formation

SOOT FORMATION ANALYSIS

IN TURBULENT DIFFUSION FLAMES

Turbulent diffusion flames are widely used in industry because of their safety. Nevertheless, their efficieticy and the pollution emission depend on the organization of the combustion medium and this fact needs the knowledge on the structure of flame. The experimental measurement of the instantaneous and local values of oxygen and fuel is very difficult, and sometime, is impossible inside the combustion chamber. So the prediction by the mathematical model is very helpful.
 
In this paper a model for calculating of soot formation in turbulent diffusion flames is presented. The turbulent nonpremixed combustion process is modeled via the conserved scalar model where the fraction mixture f is chosen as conserved scalar. The soot formation is calculated via Tesner-Magnussen model. The equations system is closed by k-e turbulence model. Experimental data obtained from diffusion flames in air and diffusion cmbustion in Diesel engines are used for model evaluation. Soot fraction in the flames is measured by light scattering method. The two-color method is used for temperature and soot distribution analysis in combustion chamber. The resuts given by the model are good coherent with the experimental data in flames and in direct injection engine. The swirl phenomena and exchange between pre-chamber and main chamber should be incorporated to the model for indirect injection engine.