Imprint of Vortical Structures on the Near-Field Pressure of a Turbulent Jet

The distributions of turbulent scales in a Mach 0.9 isothermal round jet are investigated for the purpose developing linear surface-based models noise source that can be informed by Reynolds-averaged Navier–Stokes (RANS) solution flowfield. is calculated large-eddy simulation (LES), which enables computation two-point space–time correlations throughout and its near-acoustic field. Time, length, convective-velocity examined on surface peak Reynolds stress (SPS), representing location most energetic eddies, “radiator surface” at boundary between rotational irrotational fields. nature different axial velocity fluctuations pressure fluctuations. Velocity-based appear to capture localized events, whereas pressure-based dominated interaction large eddies with surrounding potential flow. correlation length larger radiator than SPS, thus indicating small-scale do not make significant imprint surface. associated an emulated RANS flow compared LES-based scales. Simple relationships inferred may aid development rapid predictive models.