PLFAR

PLFAR, Lab, Option, VAR1B, VAR1E, NVAR1, VAR2B, VAR2E, NVAR2, VAL1, VAL2, VAL3, VAL4, VAL5, LDSTEP, SUBSTEP, FREQB, FREQE, PlotType, LogOpt
Plots pressure far fields and far-field parameters.

POST1: Special Purpose

Lab

Parameters to plot :

PRES	—	Acoustic parameters
PROT	—	Acoustic parameters with the y-axis rotated extrusion (not valid for 2D elements)
PLAT	—	Acoustic parameters radiated by a vibrating structural panel (not valid for 2D elements)

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 arguments VAR1B, VAR1E, NVAR1, VAR2B, VAR2E, NVAR2, and VAL1 are used when Option = SUMC, SUMP, PHSC, PHSP, SPLC, SPLP, SPAC, SPAP, DGCT, DGPL, PSCT, PSPL, TSCT, or TSPL:

VAR1B, VAR1E

Starting and ending values for the first variable associated with PlotType as described below.

When PlotType = blank (default) or SPHR: Starting and ending phi (φ) angles (in degrees) in the spherical coordinate system. Defaults to 0.

When PlotType = PLXY: Starting and ending x value in the Cartesian coordinate system. Defaults to 0.

When PlotType = PLYZ: Starting and ending y value in the Cartesian coordinate system. Defaults to 0.

When PlotType = PLXZ: Starting and ending x value in the Cartesian coordinate system. Defaults to 0.

NVAR1

Number of divisions between the starting and ending VAR1 values for data computations. Defaults to 0.

VAR2B, VAR2E

Starting and ending values for the second variable associated with PlotType as described below.

When PlotType = blank (default) or SPHR: Starting and ending theta (θ) angles (in degrees) in the spherical coordinate system. Defaults to 0 for a 3D model and 90 for a 2D extrusion model.

When PlotType = PLXY: Starting and ending y value in the Cartesian coordinate system. Defaults to 0.

When PlotType = PLYZ: Starting and ending z value in the Cartesian coordinate system. Defaults to 0.

When PlotType = PLXZ: Starting and ending z value in the Cartesian coordinate system. Defaults to 0.

NVAR2

Number of divisions between the starting and ending VAR2 values for data computations. Defaults to 0.

VAL1

VAL1 is additional input. Its meaning depends on the PlotType argument as described below.

When PlotType = blank (default) or SPHR: Radius of the sphere surface.

When PlotType = PLXY: Fixed z value for an X-Y plane in the Cartesian coordinate system. Defaults to 0.

When PlotType = PLYZ: Fixed x value for a Y-Z plane in the Cartesian coordinate system. Defaults to 0.

When PlotType = PLXZ: Fixed y value for an X-Z plane in the Cartesian coordinate system, Defaults to 0.

The arguments VAL2 through VAL5 are additional input used with certain Lab and Option settings as described below.

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 2D model extrusion in the z direction (no default).

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

VAL4

When Lab = PLAT: Mass density of acoustic fluid.

VAL5

When Lab = PLAT: Sound speed in acoustic fluid.

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 substeps (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 of a field parameter with variables (frequency, angle).
MRPM	—	Waterfall diagram of a field parameter with variables (frequency, RPM).
PLXY	—	Contour plot on an X-Y plane.
PLYZ	—	Contour plot on a Y-Z plane.
PLXZ	—	Contour plot on an X-Z plane.
SPHR	—	Contour plot on a sphere surface.

LogOpt

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

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 2D chart.

The waterfall diagram is plotted only in Cartesian coordinates.

Menu Paths

This command cannot be accessed from a menu.