  Non-linear sound propagation is investigated computationally by simulating
compressible time-developing mixing layers using the Large Eddy Simulation
(LES) approach and solving the viscous Burgers Equation. The mixing layers are
of convective Mach numbers of 0.4, 0.8 and 1.2. The LES results agree
qualitatively with known flow behavior. Mach waves are observed in the near
sound field of the supersonic mixing layer computed by the LES. These waves
show steepening typical to non-linear propagation. Further calculations using
the Burgers equation support this finding, where the initial wave slope has a
role in kicking them. No visible non-linear propagation effects were found for
the subsonic mixing layers. The effects of geometrical spreading and viscosity
are also considered.
