Analysis of the thermo-acoustic response of an aero-engine injector using compressible LES

Abstract

Lean-burn combustion technologies are becoming increasingly attractive for the next generation of aero-engines due to their emission reduction potential. However, this concept comes with the downside that the flame becomes more susceptible to thermo-acoustic instabilities. To enable the implementation of such a concept, predictive simulation methods are desirable. In this work, a reactive compressible large-eddy simulation framework was applied to a full-scale lean-burn aero-engine injector under realistic operating conditions. The thermo-acoustic response of the injector was measured in the Rolls-Royce SCARLET rig using optical and acoustic measurement technologies. Advanced postprocessing techniques were employed to obtain optically measured flame transfer function (FTF) based on OH* chemiluminescence and the acoustic response characterized by measured transmission coefficients. These data sets enabled the assessment of the high-fidelity modeling framework over several frequencies for an application-oriented configuration.