Combustion noise prediction in modern aero-engines Seminar

Combustion noise has recently been the subject of attention of both the aeroacoustic and the combustion research communities. Noise emissions from fan and jet in engines have been significantly reduced over the last decades and combustion noise appears now as a potential contributor. Two main mechanisms of combustion-noise generation have been identified: direct combustion noise, generated by the acoustic waves propagating to the outlet, and indirect combustion noise, caused by the acceleration of entropy and vorticity waves (or hot spots) through turbine blades. The prediction of combustion noise involves both an accurate simulation of the noise sources, and a precise modelling of the generation of indirect noise inside the turbine stages. In this work a hybrid tool to predict combustion is proposed, combining Large Eddy Simulations to compute the source terms in the combustion chamber, and low-order mathematical models to compute the propagation and generation of noise through turbine blades.