# RGYRO

Bulk Data Entry Includes data required to perform Rotor Dynamics analysis in Modal Frequency Response Analysis and/or Modal Complex Eigenvalue Analysis. The RGYRO Bulk Data Entry is referenced by a corresponding RGYRO Subcase Information Entry in a specific subcase.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
RGYRO RID SYNCFLG REFROTR SPDUNIT SPDLOW SPDHIGH SPEED

## Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
RGYRO 14 ASYNC 3 FREQ     55

## Definitions

Field Contents SI Unit Example
RID <INTEGER>
setid:
The SID is referenced by a RGYRO card in the Subcase Information section.

SYNCFLG
SYNC
Synchronous Rotor dynamic analysis is selected, if SYNC is input in this field.
ASYNC
Asynchronous Rotor dynamic analysis is selected, if ASYNC is input in this field.

No default

REFROTR
rotid
Reference rotor ID. This field selects the rotor that will be used in the Rotor dynamic analysis.

No default <INTEGER > 0>

SPDUNIT
RPM
Specifies that the entries SPDLOW, SPDHIGH and SPEED are input in Revolutions Per Minute.
FREQ
Specifies that the entries SPDLOW, SPDHIGH and SPEED are input in revolutions per unit time.

No default

SPDLOW Minimum rotor speed for synchronous analysis.

Default = 0.0 <Real>

SPDHIGH Maximum rotor speed for synchronous analysis.

Default = 99999.0 <Real>

SPEED
<INTEGER>
If an integer value is input, it references a RSPEED Bulk Data Entry that specifies a set of reference rotor speeds for asynchronous analysis. 2
<Real>Default = 0.0
If a real number is input, the value is considered constant and a single reference rotor speed value is specified. 2

Default = 0 <INTEGER, Real>

1. Multiple RGYRO Bulk Data Entries with the same RID cannot exist.
2. The values entered on some optional fields of the RGYRO Bulk Data Entry depend on factors such as: solution sequence used, type of analysis performed, and the value of specific parameters. The following table shows some of the optional fields and their relevance based on the listed factors. Synchronous analysis is performed when the rotor speed is equal to the modal frequency (Complex Eigenvalue Analysis) or the frequency of the forcing function (Frequency Response Analysis) and Asynchronous analysis is performed when the user-specified rotor speed is used for the analysis.
Solution Sequence Synchronous/Asynchronous Analysis Required Entry PARAM, GYROAVG Comment
Modal Frequency Response Analysis Synchronous None 0 -
Synchronous SPDLOW, SPDHIGH -1 3, 4
Asynchronous SPEED 0 -
Asynchronous SPEED -1 4
Modal Complex Eigenvalue Analysis Synchronous SPDLOW, SPDHIGH - 3, 4
Asynchronous SPEED - 4
3. When multiple rotors are present within the system being modeled, one of the rotors is chosen as a reference rotor. The speeds of the rest of the rotors are linearly dependent of the reference rotor. Scale factors S1 and S2 are used to relate the speeds.(1)
$\Omega =S1+S2*{\Omega }_{\mathit{ref}}$
Where,
Ω
Speed of a rotor (different from the reference rotor)
S1 and S2
Scale factors
Ωref
Speed of the reference rotor

The scale factors S1 and S2 will be calculated by a least-mean-square fit of the relative rotor speeds specified on the RSPINR entries (between SPDLOW to SPDHIGH of the reference rotor). If the SPDLOW or SPDHIGH values are beyond the range specified on the RSPINR entry, the values will be extrapolated from the RSPINR entry values.

4. PARAM, WR3 and PARAM, WR4 are necessary for rotor damping.