DNS of fuly turbulent jet flows in flight conditions including a canonical nozzle

Abstract

Direct numerical simulations are conducted of a canonical nozzle/jet configuration. The flow exiting the nozzle into a laminar co-flow is fully turbulent and serves as a well defined turbulent inlet condition for the study of sound radiation from fully turbulent jets. The sound radiation from this configuration is studied for three subsonic jet Mach numbers and varying co-flows. The target Reynolds number, based on jet exit centreline velocity and nozzle diameter is Rej = 7; 500 for all cases. Pressure power spectral densities (PSD) obtained from within the hydrodynamic field show that most of the energy is contained in the axisymmetric mode, although the PSD amplitudes of azimuthal modes wi..