engleski

Modeling of nitrogen pollutants in combustion systems

Nitrogen oxides (NOx) are among the main pollutants in the atmosphere. A significant amount of NOx emissions is attributable primarily to human activities, in particular the combustion of fossil fuels. This work is aimed at research and implementation of the NOx model, which is capable of modelling nitrogen-containing pollutant formation in practical combustion systems. The NOx reaction mechanisms were investigated and implemented into the CFD code FIRE. The nitrogen scheme was limited to sufficiently few homogeneous reactions to allow effective coupling with the turbulent mixing process. The effects of the turbulent fluctuations on the reaction rates when predicting NOx concentrations were modelled by using the presumed Probability Density Function (PDF) approach. The NOx model was applied and tested to the turbulent non-premixed jet diffusion flame (Sandia flame D) and the nitrogen predictions were compared to the results obtained by the Steady Laminar Flamelet Model (SLFM) and to the experimental data. The implemented NOx model was also applied for the calculation of nitrogen pollutant emission in real diesel engine configuration. The NOx predictions were compared with experimental data.

Pollutants; NOx; Combustion; Modelling.

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