Prediction of combustion-generated noise in non-premixed turbulent jet flames using large-eddy simulation

Noise generated from technical devices is an increasingly i mportant problem. Jet engines in particular produce sound levels that are not only a nuisance, bu t may also impair hearing. The noise emitted by such engines is generated by different sources, s uch as jet exhaust, fans or turbines, and combustion. Increasing restrictions on the allowable n oise-emission levels force manufacturers to design quieter engines. This, however, represents a c hallenging task, because the underlying physical phenomena of the aerodynamic sound generation are yet not entirely understood. Furthermore, design changes made to comply with noise-emission reg ulations may be accompanied by losses in performance. Numerical simulations offer promis e a a tool to address this design challenge, if adequate models are available. Specifically, the l arge-eddy simulation (LES) technique was demonstrated to be able to predict complex turbulent flow configurations [1–3].