K Mazaheri - Center of Excellence in Aerospace Systems, Sharif Univ. of Technology, Tehran, Iran. Professor of Aerospace Engineering;
A Babaei Zarch - Center of Excellence in Aerospace Systems, Sharif Univ. of Technology, Tehran, Iran. Graduate Student

Based on GRI-3 full mechanism for Methane oxidation, a novel skeletal mechanism is introduced to predict NOx and CO generation in advanced industrial gas turbine combustors. All species are categorized in three groups, and based on a production rate analysis, nine species are selected. Then a sensitivity analysis of this nine species and also a reaction path analysis is used to select 20 species and 35 elementary reactions, which is called here the 35 step skeletal mechanism. The overall validity of this mechanism is confirmed by comparing results of the present model for a fairly wide range of operating conditions with GRI-3 full mechanism in several reactors, i.e. a PSR reactor, a PSR-PFR reactor, and a premixed reactor. The adiabatic flame temperature and all of the main products, and also the trend of productions are well predicted. Furthermore, the error of predicted pollutants (NO2, NO and CO) concentration is often less than 10%. The speed up of the skeletal mechanism respect to the full mechanism in a premixed reactor is about 8.9 times. The mechanism is also compared with two similar published skeletal mechanisms to show its advantage respect to them.

Skeletal Mechanism, Reduced Mechanism, Methane air combustion