ERP

I/O Options and Subcase Information Entry Used to request equivalent radiated power output for all subcases or individual subcases, respectively.

Format

ERP (format_list, grid, peakoutput,MPF=mpf, MFILTER=mfilter, FREQUENCY/SOLUTION=frequency ) = option

Definitions

Argument Options Description
format H3D, PUNCH, blank
H3D
Results are output in Hyper3D format (.h3d file).
PUNCH
Results are output in Nastran punch results format (.pch file).
blank (Default)
Results are output in all active formats for which the result is available.
grid GRID

Default = blank

GRID
Output the contribution of each grid in addition to the ERP results for the PANEL, defined by ERPPNL or PANELG (TYPE=ERP). 5
peakoutput PEAKOUT

Default = blank

If present, then only the filtered frequencies from the PEAKOUT card will be considered for this output.
mpf ALL, <N>

Default = blank

ALL
Modal Participation Factors are output for ALL modes.
<N>
Modal Participation Factors are output for the specified <N> modes.
(Integer)
frequency <SETID>

Default = blank

<SETID>
Indicates the SET of loading frequencies for which Modal Participation Factors should be output. If not specified, then Modal Participation Factors are output for all loading frequencies.
(Integer)
mfilter <Real>

Default = blank

Provides a threshold under which Modal Participation Factors are not output. Output is skipped when the Modal Participation Factor divided by the maximum Modal Participation Factor (for the current mode) is below the threshold specified by MFILTER.
option <YES, ALL, NO, NONE>

Default = ALL

YES, ALL, blank
Equivalent radiated power is output for all panels.
NO, NONE
Equivalent radiated power is not output.

Comments

  1. Multiple formats are allowed on the same entry; these should be comma separated. If a format is not specified, this output control applies to all formats defined by the OUTPUT command, for which the result is available.
  2. Multiple instances of this card are allowed. If instances are conflicting, the last instance dominates.
  3. For optimization, the frequency of output to a given format is controlled by the I/O option OUTPUT.
  4. In addition to the ERP values, the following results are output to the .pch file: total ERP over the loading frequencies, fraction of the total ERP at each loading frequency, and ERP expressed in decibels ERPdB = 10 * log10 (ERP) at each loading frequency.
  5. The ERP output of a panel is calculated, as shown in Equation 2. The parameters for the speed of sound (ERPC), fluid density (ERPRHO), and radiation loss factor (ERPRLF) are used in the calculation of ERP.
    (1)
    E R P = E R P R L F * ( 1 2 E R P C * E R P R H O ) i n g r i d A i v i 2 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaebbnrfifHhDYfgasaacH8srps0l bbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr0R Yxir=Jbba9q8aq0=yq=He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGa caGaaeqabaqaaeaadaaakeaacaWGfbGaamOuaiaadcfacqGH9aqpca WGfbGaamOuaiaadcfacaWGsbGaamitaiaadAeacaGGQaWaaeWaaeaa daWcaaqaaiaaigdaaeaacaaIYaaaaiaadweacaWGsbGaamiuaiaado eacaGGQaGaamyraiaadkfacaWGqbGaamOuaiaadIeacaWGpbaacaGL OaGaayzkaaWaaabCaeaacaWGbbWaaSbaaSqaaiaadMgaaeqaaOGaam ODamaaDaaaleaacaWGPbaabaGaaGOmaaaaaeaacaWGPbaabaGaamOB aiaadEgacaWGYbGaamyAaiaadsgaa0GaeyyeIuoaaaa@5346@
    The ERP output of a grid point ( i ) is also calculated similar to that of a panel (as shown above). The parameters for the speed of sound (ERPC), fluid density (ERPRHO), and radiation loss factor (ERPRLF) are used in the calculation of ERP output for a particular grid.(2)
    ( ERP ) i =ERPRLF( 1 2 ERPC×ERPRHO ) A i v i 2 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca WGfbGaamOuaiaadcfaaiaawIcacaGLPaaadaWgaaWcbaGaamyAaaqa baGccqGH9aqpcaWGfbGaamOuaiaadcfacaWGsbGaamitaiaadAeada qadaqaamaalaaabaGaaGymaaqaaiaaikdaaaGaamyraiaadkfacaWG qbGaam4qaiabgEna0kaadweacaWGsbGaamiuaiaadkfacaWGibGaam 4taaGaayjkaiaawMcaaiaadgeadaWgaaWcbaGaamyAaaqabaGccaWG 2bWaa0baaSqaaiaadMgaaeaacaaIYaaaaaaa@5318@
    Where,
    v i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaebbnrfifHhDYfgasaacH8srps0l bbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr0R Yxir=Jbba9q8aq0=yq=He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGa caGaaeqabaqaaeaadaaakeaacaWG2bWaaSbaaSqaaiaadMgaaeqaaa aa@33D0@
    Normal velocity
    A i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaebbnrfifHhDYfgasaacH8srps0l bbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr0R Yxir=Jbba9q8aq0=yq=He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGa caGaaeqabaqaaeaadaaakeaacaWGbbWaaSbaaSqaaiaadMgaaeqaaa aa@339B@
    Associate area of each grid on the panel
  6. The calculation of ERP in decibels (dB) is performed using the PARAM data RHOCP and ERPREFDB in Equation 3. ERPREFDB is the reference value in dB and RHOCP is the scale factor:(3)
    ERP dB = 10 log 10 ( RHOCP * ERP ERPREFDB )
  7. At least one of the Bulk Data Entries ERPPNL or PANELG (TYPE=ERP) needs to be specified, if the ERP Output Request is used.
  8. Modal Participation Factor output for Equivalent Radiated Power is supported in PUNCH and H3D files. Either FREQUENCY or SOLUTION can be used as the keyword to indicate the loading frequency set.
  9. The direction of normals of elements selected as a panel for ERP output should be consistent. OptiStruct will automatically flip normals of elements which have inconsistent normals if such elements belong to panels selected for ERP output.