FWH_OUTPUT

Specifies output parameters for the Ffowcs-Williams Hawkings (FWH) method that is used by the AcuFwh post processing program to propagate acoustic sources to far field locations.

Type

AcuSolve Command

Syntax

FWH_OUTPUT{parameters...}

Qualifier

None.

Parameters

reference_density or ref_dens (real) [=1.225]
Reference density. Required to compute the output quantities.
reference_pressure or ref_pres (real) [=0]
Reference pressure. Required to compute the output quantities.
reference_sound_speed or sound (real) [=330]
Reference sound speed. Required to compute the output quantities.
source_output_frequency or out_freq (integer) >=0 [=0]
Time step frequency at which to output FWH data. If zero, this option is ignored.
source_output_time_interval or out_intv (real) >=0 [=0]
Time frequency at which to output the FWH data. If zero, this option is ignored.
num_saved_states or save (integer) >=0 [=0]
Number of FWH data files to keep. If zero, all are kept.

Description

This command specifies the FWH output data properties to support Ffowcs-Williams Hawkings (FWH) post-processing. For example,
FWH_OUTPUT{
 reference_density           = 1.225
 reference_pressure          = 0
 reference_sound_speed       = 330
 source_output_frequency     = 1
 source_output_time_interval = 0
 num_saved_states            = 0
}

The parameters reference_density, reference_pressure and reference_sound_speed provide the required data for the computation of the output fields. An AcuSolve input file should only contain one FWH_OUTPUT command.