Identification of sound sources in ducted flows with an LES-SI-DMD approach: Influence of mesh refinement and subgrid scale models

Abstract

Anovel computational approach for the prediction of aeroacoustic sources based on Large Eddy Simulation and System Identification is presented. The objective is to characterize concurrently both the scattering of acoustic waves and the generation of noise at flow discontinuity in a duct. The methodology is outlined and applied to an orifice placed inside a pipe with turbulent flow. Results for the passive acoustic scattering are compared with experiment. The noise sources obtained from LES with and without an external acoustic excitation are compared for a variety of simulation settings. The influences of mesh resolution and of the subgrid scale models are investigated. Flow features responsible for noise generation are educed with dynamic mode decomposition.