The predictive capabilities of two candidate approaches for CO predictions were assessed for a series of aircraft gas turbine combustors. The first approach involved constructing a large reduced order reactor network coupled with a detailed, 500 species n-dodecane mechanism to simulate the combustion process. The second approach was the traditional RANS based CFD using two finite rate based combustion models in FLUENT. A four step Jet-A global mechanism was developed in-house and was used in the CFD simulations. The global mechanism was validated against the detailed Jet-A mechanism published by Dagaut in 2006 and was able to reproduce the flame speed and species profiles satisfactorily over the range of relevant operating temperatures and pressures. The calibration combustors comprised seven configurations with identical fuel nozzles but different swirlers, dome effusion, liner and quench jet air flow splits. It was found that the CFD approach was better at capturing the trend of rig data, than the reactor network approach and was able to capture most of the variations seen in the measurement. The improvement in prediction was attributed mainly to the more accurate global mechanism which results in more accurate kinetic calculation in CFD.
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