12.3. Postprocessing a Modal Acoustic Analysis

Results from an acoustic analysis are written to the results file Jobname.rst. Results include the following:

Primary data: Nodal DOFs (UX, UY, UZ, PRES) and resonant frequencies

Derived data:

  • Nodal sound pressure level

  • Nodal velocity, sound intensity, or energy density flux (room acoustics)

  • Element velocity (PGX, PGY, PGZ, PGSUM), energy density flux (room acoustics), or sound intensity (SNDIX, SNDIY, SNDIZ, SNDISUM)

  • Element average pressure amplitude

  • Square of the L2 norm of pressure over element volume

  • Acoustic potential energy in element (MENE)

  • Acoustic kinetic energy in element (KENE)

In modal analysis, the time-average root mean square quantities are calculated over one period of the sinusoidal function. For more information, see Elements for Acoustic Analysis in the Element Reference.

Use the POST1 general postprocessor (/POST1) to view results over the entire model at specific resonant frequencies. To view results over a range of frequencies, use the POST26 time history postprocessor (/POST26).

For a complete description of all postprocessing functions, see An Overview of Postprocessing the Basic Analysis Guide.