“Synchronized Large-Eddy Simulations for Sound Generation Analysis"
We employ a new technique comprised of multiple simultaneous Large-Eddy Simulations (LES) to analyze the dynamics of turbulence, with emphasis on jet noise. Unlike methods which seek to use correlation of signals at different locations, here we isolate and tag perturbations in different regions of interest and examine the manner in which they are modulated and filtered by the turbulence. The technique essentially uses two (or more) simultaneous, synchronized Large Eddy Simulations (LES). One, denoted baseline, provides the natural perturbations existing in the jet. These are processed and injected into a twin to provide a perturbation boost, which can then be tracked in the twin. Several simulations on a Mach 1.3 cold jet demonstrate the effectiveness of the approach in determining the self and mutual interactions in core turbulence that ultimately yield the near acoustic field. Detailed 1-D and 2-D statistical analyses yield unique insight into the nature of intermittency, spatio-temporal correlations, wave-packet generation and directivity.