Prediction of NO_x for Double Annular Combustors using stirred reactor approach

摘要

The current research assesses the feasibility of predicting the NO_x emissions for Double Annular Combustors (DAC) using the stirred-reactor approach. Three major types of reactor models, namely perfectly stirred reactor (PSR), partially stirred reactor (PaSR) and series of perfectly stirred reactor (PSRs) are developed for modelling the fuel-air mixing characteristics. Chemical kinetics models are also employed to quantify NO_x production by calculating the formation rate. The DAC model is validated against three combustors, namely E~3 program baseline DAC and International Civil Aviation Organisation (ICAO) data for CFM56-5B4/2P and GE 90-115B DAC combustors. The model is capable of providing satisfactory prediction results for NO_x emissions for the E3 double annular combustor, particularly at high power settings, where there is only 0.6% and 0.22% deviation from test data respectively. Similar results are obtained for CFM56-5B4/2P and GE 90-115B DAC combustors case studies with emissions trend captured reasonably at high power settings. Although the predictions for low power setting emissions display a relatively larger discrepancy, the general trends are well captured, which allows its application optimisation and trade-off studies for preliminary combustor design.