Direct Computation of the Sound Radiated from a Diffusion Jet Flame Using Large Eddy Simulation

摘要

With the introduction of high-by-pass ratio engines to reduce jet exhaust noise, other sources such as combustion and core noise have become more prominent. A Large eddy simulation (LES) of sound generation by a turbulent diffusion jet flame is presented. The compressible Navier-Stokes equations are solved so that the results include both combustion and acoustic propagation. Combustion noise has monopolar characteristics for low frequencies. For high frequencies, the sound field is no longer omni-directional. Major sources of sound seems to be located in the jet shear layer within one potential core length from the jet nozzle and are believed to be associated with reaction zone wrinkling.