Three-dimensional interactions in large-eddy simulation of a warm complex supersonic jet¹

We document the correlations between far-field acoustics and near-field pressure fluctuations related to the two-stream supersonic rectangular jet with sonic wall jet over a deck plate. The near field data (velocity, pressure and density) is generated by JENRE, an LES code produced by the Naval Research Laboratory. The data is sampled along various section planes, and in three-dimensional regions previously identified as active. From this data, a Ffowcs-Williams-Hawking procedure generates the far filed acoustics, with signals collected along two perpendicular arcs, one in the jet’s plane of symmetry and one parallel to the deck. Periodic activity in the far-field signals serves as a flow marker, and cross-correlations between the band-pass-filtered acoustic signals and the near-field pressure shows that different flow structures are involved in the low-frequency pulsing and in the modulation of the high-frequency fluctuations. Significant spanwise variations are observed.