Numerical simulation of a Mach 1.92 turbulent jet and its sound field

A perfectly expanded turbulent Mach 1.92 jet is simulated by direct numerical solution of the compressible Navier-Stokes equations in a computational domain that includes the near acoustic field. In place of a nozzle, turbulent inflow data were generated in a separate streamwise periodic jet simulation. Reynolds stresses, two-point correlations, and turbulent energy spectra are computed and discussed. The sound field is highly directional and dominated by Mach waves as are commonly observed experimentally. Analysis of the sound using weak-shock theory shows that nonlinear effects are significant away from the jet but that linear theory is sufficient to estimate near-field sound pressure levels. Although no attempt was made to match any particular experiment in detail, sound pressure levels are compared with experimental data at similar how conditions and are found to agree in general with jets at similar convective Mach numbers.