RSPINT
Bulk Data Entry Defines the rotor spin rates and rotor damping parameters with respect to time during a Transient Rotor Dynamics Analysis.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
RSPINT | ROTORID | GRIDA | GRIDB | SPDUNIT | SPTID | ||||
GR | ALPHAR1 | ALPHAR2 | WR3R | WR4R | WRHR | HYBRID |
Example
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
RSPINT | 140 | 2500 | 2501 | FREQ | 300 | ||||
0.04 |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
ROTORID |
No default <Integer > 0> |
|
GRIDA | Identifies a grid on the
Rotor Line Model (ROTORG) or 3D rotor axis
(ROTOR). GRIDA and GRIDB define the positive rotor spin direction. The vector connecting GRIDA and GRIDB is the positive direction vector. For 1D rotors, the rotor axis is defined using the ROTORG Bulk Data Entry and the two grids (GRIDA, GRIDB) are also specified on the ROTORG Bulk Data Entry. For 3D rotors, the rotor axis is defined using the ROTOR Bulk Data Entry. No default <Integer > 0> |
|
GRIDB | Identifies a grid on the
Rotor Line Model (ROTORG) or 3D rotor axis
(ROTOR). GRIDA and GRIDB define the positive rotor spin direction. The vector connecting GRIDA and GRIDB is the positive direction vector. For 1D rotors, the rotor axis is defined using the ROTORG Bulk Data Entry and the two grids (GRIDA, GRIDB) are also specified on the ROTORG Bulk Data Entry. For 3D rotors, the rotor axis is defined using the ROTOR Bulk Data Entry. No default <Integer > 0> |
|
SPDUNIT |
No default |
|
SPTID |
No default |
|
GR | Rotor structural damping factor. 4
5 Default = 0.0 <Real> |
|
ALPHAR1 | Scale factor applied to the rotor mass matrix for Rayleigh
damping. 5
6 Default = 0.0 <Real> |
|
ALPHAR2 | Scale factor applied to the rotor stiffness matrix for Rayleigh
damping. 5
6 Default = 0.0 <Real> |
|
WR3R | Average excitation frequency for calculation of rotor damping and
circulation terms for rotor structural damping specified through
GR field. Default = 0.0 <Real> |
|
WR4R | Average excitation frequency for calculation of rotor damping and
circulation terms for rotor structural damping specified through
GE (material, bushing etc.)
entries. Default = 0.0 <Real> |
|
WRHR | Average excitation frequency for calculation of rotor damping and
circulation terms for rotor structural hybrid damping specified
through HYBRID entry. Default = 0.0 <Real> |
|
HYBRID | Hybrid damping. References the identification number of a
HYBDAMP entry for hybrid damping
specification. 6 Default = 0 <Integer ≥ 0> |
Comments
- A RSPINR or RSPINT Bulk Data Entries must exist for each rotor, whether the rotor is defined as a 1D rotor (ROTORG) or 3D rotor (ROTOR).
- GRIDA and GRIDB define the positive rotor spin direction. The vector connecting GRIDA and GRIDB is the positive direction vector. For 1D rotors, the rotor axis is defined using the ROTORG Bulk Data Entry and the two grids (GRIDA, GRIDB) are also specified on the ROTORG Bulk Data Entry. For 3D rotors, the rotor axis is defined using the ROTOR Bulk Data Entry.
- The TABLED1 entry can be used to specify the various rotor speeds with respect to time. The time values are specified on the X-Axis and the corresponding rotor speeds are defined on the Y-Axis.
- Rotor structural damping factor (
) can be incorporated as either equivalent viscous
damping or structural damping depending on the solution sequence.
Or,
Where, WR3 is a parameter defined as a field on RSPINT entry, or by PARAM, WR3. In case both are defined, then WR3 on RSPINT takes precedence. GR is defined as a field on the RSPINT Bulk Data Entry.
The selection depends on the following factors:- Modal frequency response or Complex eigenvalue analysis
- Synchronous or Asynchronous solutions
- Value of PARAM, GYROAVG
- The Rayleigh damping
value for the rotor is calculated from ALPHA1 and
ALPHA2.
and
are used to define the Rayleigh viscous damping
as:
and
- For detailed information on how each type of rotor damping enters into the system equations through their corresponding damping and circulation terms. Refer to Rotor Dynamics in the User Guide.
- Rotor damping is cumulative and caution should be exercised when multiple damping effects are assigned.