EFFECT OF AXIAL SWIRLER PARAMETERS ON A METHANEAIRCOMBUSTION CHARACTERISTICS AND FORMATION OF NITROGEN OXIDE

Анотація

CFD simulation of none-premixed methane-air combustion is performed. The purpose of this paper is to provide information concerning the effect of geometry of axial swirler vanes on the exhaust gas emissions of oxides of nitrogen (NO), for a can combustor of gas turbine engine. Effects of different swirler vane angles on NO formation, are shown. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and air-fuel mixing enhancement. Therefore designing an appropriate air swirler is a challenge to produce stable, efficient and low emission of combustion with low pressure losses. Five axial flat vane swirlers with 20°, 30°, 45°, 55°, and 60° vane angle corresponding to swirl number of0.28, 0.444, 0.769, 1.1 and 1.33 respectively, were used in this analysis to show vane angle effect on the internal flow field, temperature fluctuations and formation of NO. The simulation has been performed using the Computational Fluid Dynamics (CFD) commercial code ANSYS CFX release 16, including laminar flamelet model, for simulating the methane combustion mixing with air .k-e model was also investigated to predict the turbulent combustion reaction. A thermal and prompt NOx formation is performed for predicting NO emission characteristics.