**AEROCOEFF**, * AeroModeType*,

`AeroMappedFileNames`

`AeroSpecs`

`AeroScalar`

`nBlades`

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

`AeroModeType`

Mode type to be used.

**BLADE**—

Non-cyclic cantilevered blade mode (default)

`AeroMappedFiles`

Name of string array containing file names of mapped pressures from CFD. The file names should be ordered to correspond to the

array.`AeroSpecs`

`AeroSpecs`

Name of numerical array containing data organized to correspond to the

array. See the "Notes" section for specific information that must be in the array.`AeroMappedFiles`

`AeroScalar`

Scaling value(s) to handle any modal scaling difference between structural and CFD modes. The values can be entered as a scalar or 1-dimensional array. (each scaling value defaults to 1)

`nBlades`

Number of blades.

The **AEROCOEFF** command is designed to generate an array of aerodynamic coefficients that
can be used in a cyclic mode-superposition harmonic response analysis using the
**CYCFREQ**,AERO command to represent aerodynamic stiffness and damping.
These aerodynamic coefficients can also be used in a damped modal analysis phase
(**CYCFREQ**,MODAL) of a cyclic mode-superposition harmonic solve. An APDL
array called * Jobname*AeroArray is generated using the

The format of the written array follows that of the **CYCFREQ**,AERO
command. The array is formatted as follows:

where

= the i^{th} interblade phase angle
(IBPA) |

= the m^{th} vibrating blade mode |

= the n^{th} blade mode generating the pressure
oscillations |

and = the real and imaginary coefficients. |

Prior to issuing the **AEROCOEFF** command, a non-cyclic cantilevered blade
modal analysis must be run, either stress-free or prestressed using linear perturbation. For
more information, see Modal Analysis in the *Structural Analysis Guide*. The file requirements
for the **AEROCOEFF** command are the same as those needed for modal restart as
described in Modal Analysis Restart.

The * AeroSpecs* values are specified in a 3×r array
(

where

= the i^{th} interblade phase angle
(IBPA) |

= the m^{th} vibrating blade mode |

= the n^{th} blade mode generating the pressure
oscillations |

At least one aerodynamic damping coefficient must be specified for each IBPA (equal to the number of blades) while keeping and constant. If a value is not specified, the program writes an array value of zero for both and . The values of and are relative to the modes computed in the required modal analysis.

The number of * AeroScalar* values must be equal to the number of
pressure modes ( from

`AeroSpecs`

`AeroScalar`

`AeroScalar`

`AeroScalar`

The value for * nBlades* should be equal to the number of sectors
of the system. If there are multiple blades per cyclic sector, then the combination of blades
on the single sector will have an aero coefficient value. In this case, each blade will not
have a distinct aero coefficient.