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

Noise generated from technical devices is an increasingly important problem. Jet engines in particular produce sound levels that are not only a nuisance, but may also impair hearing. The noise emitted by such engines is generated by different sources, such as jet exhaust, fans or turbines, and combustion. Increasing restrictions on the allowable noise-emission levels force manufacturers to design quieter engines. This, however, represents a challenging 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 regulations may be accompanied by losses in performance. Numerical simulations offer promise as a tool to address this design challenge, if adequate models are available. Specifically, the large-eddy simulation (LES) technique was demonstrated to be able to predict complex turbulent flow configurations [1–3].