PLFAR

PLFAR

PLFAR, Lab, Option, PHI1, PHI2, NPH1, THETA1, THETA2, NTHETA, VAL1, VAL2, VAL3, VAL4, VAL5, LDSTEP, SUBSTEP, FREQB, FREQE, PlotType, LogOpt
Plots pressure far fields and far field parameters.

POST1: Special Purpose

Compatible Products: – | – | – | Enterprise | Ent PP | Ent Solver | –

Lab

Parameters to plot :

PRES	—	Acoustic parameters
PROT	—	Acoustic parameters with the y-axis rotated extrusion
PLAT	—	Acoustic parameters radiated by a vibrating structural panel

Option

Plot option, based on the specified plot parameter type:

Lab Option

`Lab`	`Option`
PRES, PROT, or PLAT	SUMC -- Maximum pressure in Cartesian coordinate system plot (default) SUMP -- Maximum pressure in polar coordinate system plot PHSC -- Pressure phase angle in Cartesian coordinate system plot PHSP -- Pressure phase angle in polar coordinate system plot SPLC -- Sound pressure level in Cartesian coordinate system plot SPLP -- Sound pressure level in polar coordinate system plot SPAC – A-weighted sound pressure level in Cartesian coordinate system plot (dBA) SPAP – A-weighted sound pressure level in polar coordinate system plot (dBA) DGCT -- Acoustic directivity in Cartesian coordinate system plot DGPL -- Acoustic directivity in polar coordinate system plot PSCT -- Maximum scattered pressure in Cartesian coordinate system plot PSPL -- Maximum scattered pressure in polar coordinate system plot TSCT -- Target strength in Cartesian coordinate system plot TSPL -- Target strength in polar coordinate system plot PWL -- Sound power level

PRES, PROT, or PLAT

SUMC -- Maximum pressure in Cartesian coordinate system plot (default)

SUMP -- Maximum pressure in polar coordinate system plot

PHSC -- Pressure phase angle in Cartesian coordinate system plot

PHSP -- Pressure phase angle in polar coordinate system plot

SPLC -- Sound pressure level in Cartesian coordinate system plot

SPLP -- Sound pressure level in polar coordinate system plot

SPAC – A-weighted sound pressure level in Cartesian coordinate system plot (dBA)

SPAP – A-weighted sound pressure level in polar coordinate system plot (dBA)

DGCT -- Acoustic directivity in Cartesian coordinate system plot

DGPL -- Acoustic directivity in polar coordinate system plot

PSCT -- Maximum scattered pressure in Cartesian coordinate system plot

PSPL -- Maximum scattered pressure in polar coordinate system plot

TSCT -- Target strength in Cartesian coordinate system plot

TSPL -- Target strength in polar coordinate system plot

PWL -- Sound power level

The following arguments PHI1, PHI2, NPHI, THETA1, THETA2, and NTHETA are used only when Option = SUMC, SUMP, PHSC, PHSP, SPLC, SPLP, SPAC, SPAP, DGCT, DGPL, PSCT, PSPL, TSCT, and TSPL:

PHI1, PHI2

Starting and ending φ angles (degrees) in the spherical coordinate system. Defaults to 0.

NPHI

Number of divisions between the starting and ending φ angles for data computations. Defaults to 0.

THETA1, THETA2

Starting and ending θ angles (degrees) in the spherical coordinate system. Defaults to 0 for a 3-D model and 90 for a 2-D extrusion model.

NTHETA

Number of divisions between the starting and ending θ angles for data computations. Defaults to 0.

VAL1

Radius of the sphere surface. Used only when Option = SUMC, SUMP, PHSC, PHSP, SPLC, SPLP, SPAC, SPAP, DGCT, DGPL, PSCT, PSPL, TSCT, or TSPL.

VAL2

When Option = SPLC, SPLP, SPAC, or SPAP: Reference rms sound pressure. Defaults to 2x10^-5 Pa.

When Option = PWL: Reference sound power. Defaults to 1x10^-12 watts.

VAL3

When Lab = PRES: thickness of 2-D model extrusion in the z direction (no default).

When Lab = PROT: angle of the y-axis rotated extrusion model (no default).

VAL4

Mass density of acoustic fluid; used only when Lab = PLAT.

VAL5

Sound speed in acoustic fluid; used only when Lab = PLAT.

LDSTEP

Specified load step. Defaults to the load step number specified on the SET command, or defaults to 1 if SET has not been issued.

*`n`*	—	Load step number.
ALL	—	All load steps.

SUBSTEP

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.

*`n`*	—	Substep number.
ALL	—	All substeps.

FREQB

Frequency value representing one of the following:

Beginning frequency of the frequency range (FREQB to FREQE) for the defined load step(s) and substeps (SUBSTEP = ALL). If a SUBSTEP value is specified, FREQB is invalid.
Central frequency of octave bands, used when LogOpt = OB1, OB2, OB3, OB6, OB12, or OB24 and FREQE is blank.

FREQE

Ending frequency of the frequency range (FREQB to FREQE) for the defined load step(s) and sub-steps (SUBSTEP = ALL). If blank, FREQE is set to FREQB. If a SUBSTEP value is specified, FREQE is invalid.

PlotType

Type of plot:

ANGX	—	x-y chart with angle as the x-axis variable (default).
FRQX	—	x-y chart with frequency as the x-axis variable.
CONT	—	Waterfall diagram with a field parameter contour.

LogOpt

Octave bands (used only when Option = SPLC, SPLP, SPAC or SPAP):

OB0	—	Narrow bands (default).
OB1	—	Octave bands.
OB2	—	1/2 octave bands.
OB3	—	1/3 octave bands.
OB6	—	1/6 octave bands.
OB12	—	1/12 octave bands.
OB24	—	1/24 octave bands.

Notes

The PLFAR command plots pressure far fields and far field parameters as determined by the equivalent source principle. Use this command to plot pressure and acoustic parameters. See the HFSYM command for the model symmetry and the HFANG command for spatial radiation angles.

Plotting acoustic parameters radiated by a vibrating structural panel (Lab = PLAT) is supported by elements SOLID185, SOLID186, SOLID187, SHELL181, SHELL281, and SOLSH190. The vibration surface of the panel must be flagged by the SF,,MXWF command.

A maximum of ten curves can be plotted on a 2-D chart.

The waterfall diagram displays the field parameter contour with variables (frequency, angle), except for sound power level which has the variables (frequency, rpm). The waterfall diagram is plotted only in Cartesian coordinates.

Menu Paths

This command cannot be accessed from a menu.