Prints a specified acoustic quantity during postprocessing of an acoustic analysis.
The acoustic quantity to calculate:
Specific acoustic impedance on the selected surface.
Acoustic impedance on the selected surface.
Mechanical impedance on the selected surface.
Average pressure on the selected surface.
Force on the selected surface.
Acoustic power on the selected surface.
Frequency-band sound pressure level on selected nodes.
A-weighted frequency-band sound pressure level on selected nodes.
Acoustic potential energy on the selected elements.
Acoustic kinetic energy on the selected elements.
Acoustic total energy on the selected elements.
Average square of the L2 norm of pressure on the selected elements.
Input sound power level on defined port.
Output sound power level on defined driven port.
Return loss on defined port.
Absorption coefficient on defined port.
Transmission loss on defined ports.
All port-related parameters (LWIN, LWOUT, RL, ALPHA, TL).
Transmission loss of random acoustic analysis.
Radiated power in random acoustic analysis.
All random acoustic related parameters (DFSTL, DFSPW).
Load step number.
All load steps.
AVG or 0
Average result of multiple samplings in a random acoustic analysis (see the
MSOLVE command). This option is used only for
Specified substep. Defaults to the substep number specified on the SET
command, or defaults to ALL (all substeps at the specified load step) if
SET has not been issued. For
Lab = BSPL or
BSPA, ALL is the only valid value.
Frequency value representing one of the following:
Beginning frequency of the frequency range (
FREQE) for the defined load step(s) and substeps
SUBSTEP = ALL). If a
FREQB is invalid.
Central frequency of octave bands, used when
LogOpt = OB1,
OB2, OB3, OB6, OB12, or OB24 and
FREQE is blank.
Ending frequency of the frequency range (
FREQE) for the defined load step(s) and sub-steps
SUBSTEP = ALL). If blank,
FREQE is set
FREQB. If a
SUBSTEP value is
FREQE is invalid.
Narrow bands (default).
1/2 octave bands.
1/3 octave bands.
1/6 octave bands.
1/12 octave bands.
1/24 octave bands.
Input port number for
Lab = LWIN, LWOUT, RL, ALPHA, TL, or
Output port number for
Lab = TL or PALL.
Reference power for
Lab = LWIN, LWOUT, PALL or EPRL (defaults
to 1x10-12 W).
Fluid mass density for
Lab = ERP or ERPL (defaults to 1.2041
Speed of sound in the fluid for
Lab = ERP or ERPL (defaults to
Radiation efficiency for
Lab = ERP or ERPL (defaults to
The PRAS command lists the specified acoustic quantity on the selected exterior surface, the energy on selected elements, or the sound pressure level over frequency bands. The calculation is based on the pressure and velocity solution or the frequency-band sound pressure level (SPL).
The total pressure and velocity are used if the selected surface is the excitation source surface. To calculate the incoming and outgoing acoustic power and other sound power parameters on the input and output surfaces, issue the SF,,PORT command in the preprocessor to define port numbers.
The sound pressure level of the octave bands and general frequency band (defined via the HARFRQ command) is calculated at the selected nodes in the model.