Postprocessing of Direct Aeroacoustic Simulations Using Helmholtz Decomposition

The decomposition of a compressible velocity field is formulated into pure vortical and pure compressible structures for any flow domain within the finite element framework. In particular, two different formulations of the Helmholtz decomposition are compared and the superiority of the vector potential formulation is demonstrated concerning general domains. The application of the decomposition to a compressible flowfield over a rectangular cavity at Mach 0.8 shows promising results for further applications and the development of acoustic boundaries in fluid dynamics. To conclude, the presented formulation is a powerful tool to postprocess direct aeroacoustic simulations.