Investigation and Modeling of Combustion instabilities in Aero Engines

Combustion instability results from a coupling between acoustic and heat release fluctuations. From the analysis of published works by various research teams including ONERA, this paper describes the coupling lines involved, the model used to describe it and the methods developed to predict the thermo-acoustic risks. The application is focused on the liquid-fueled aero engine specificities. Recent results obtained at ONERA on the influence of the liquid flow behavior on these couplings are described and compared with LES results.