Bulk Data Entry Used to activate dB and dB(A) output in H3D and PUNCH file formats for Fluid-Structure
Coupled Frequency Response Analysis.
Parameter
Values
Description
PREFDB
Real > 0.0
No
default
This parameter specifies
the reference pressure value used to calculate the pressure level in
decibels (dB) and A-weighted decibels (dB(A)).
The pressure level
in decibels (dB) can be calculated using the following
equation:
Where,
Pressure level in decibels (dB)
Magnitude of the pressure from Coupled
Fluid-Structure Frequency Response Analysis
Reference sound pressure value specified using this
parameter
Note:
The pressure level in decibels (dB or dB(A)) is not
output unless
PARAM,PREFDB,<value>
is specified.
If this parameter is specified without a value, then an
error is issued.
In the PUNCH file, within the PRESSURE (dB, dBA)
section, the first two values printed for each frequency
are the pressure level output in dB and dB(A) formats.
The remaining values of each frequency are set to 0.0
for formatting purposes.