Abstract by Kevin Leete
Physics and Astronomy
Coherence analysis of the simulated sound field of a highly-heated laboratory-scale jet
Large-eddy simulations (LES) have been shown to reproduce the flow and acoustic fields of laboratory-scale jets, and recent improvements have allowed for simulations of temperatures on the order of those produced by military aircraft operating at afterburner. This work applies coherence analyses (which were developed for measurements of military aircraft jet noise) to the LES of a highly-heated laboratory-scale jet. The coherence of the complex pressures along a near-field line shows evidence of four field regions with differing characteristics. The coherence between this line and complex pressures along the simulated nozzle lipline provide source regions in the jet plume corresponding to each field region. Differences in how information is transferred from the flow to the field suggests that different source mechanisms are responsible for each region. These field regions compare favorably to some spatiospectral lobe features observed in measurements of an F-35B aircraft operating at afterburner, though do not reproduce all the phenomena present in the aircraft's jet noise field.