The primary objective was to compare the emission data measured on CFM56-2C1 engine during APEX (Aircraft Particle Emission eXperiment) campaign by NASA. Four engine operating conditions, idle/taxi, approach, climb and take-off have been considered. NOx emission has been predicted in fair agreement with the APEX data. CO was highly over-predicted whereas CH and C2H2 were under-predicted. Several contours of different variables such as temperature, pressure, velocity, mass fraction of major species have been analyzed to understand the physics and chemistry inside the combustion chamber
