Access the phase information of acoustic pressure in aero-acoustic simulations

  • Last Post 17 October 2017
admin posted this 27 September 2017

How do I access the phase information of acoustic pressure in aero-acoustic simulations?

Arun Kumar posted this 17 October 2017

First, run a transient CFD-simulation using the FWH acoustics model, and record asd-files in regions of interest (asd: acoustic source data). After the simulation, enable beta-features (use the TUI: define/beta-feature-access yes yes), go to "Run Calculation", and select "Acoustic Sources FFT". In the "Read ASD Files" tab, select the *.index-file, which accesses all relevant asd-files. Click "Read". After, compute FFT fields in the related tab. In the "FFT Surface Variables" tab, select "Set of Modes" as "Modes/Frequency Bands", and then click "Create". Doing so creates real and imaginary parts of the complex pressure. Using them, the magnitude and the phase of the pressure signal can be computed. Phase-spectrum of phase-angle PSI: tan PSI(f) = ImY(f)/ReY(f) Magnitude-spectrum: |Y(f)| = (ReY(f)^2+ImY(f)^2)^1/2 By means of custom-field-functions, the real and imaginary parts can be combined to get the phase information.