omega

Mapdl.omega(omegx='', omegy='', omegz='', **kwargs)

Specifies the rotational velocity of the structure.

APDL Command: OMEGA

Parameters
omegx, omegy, omegz

Rotational velocity of the structure about the global Cartesian X, Y, and Z axes.

Notes

This command specifies the rotational velocity of the structure about each of the global Cartesian axes (right-hand rule). Rotational velocities may be defined in these analysis types:

Static (ANTYPE,STATIC)

Harmonic (ANTYPE,HARMIC) – Full or mode-superposition

Transient (ANTYPE,TRANS) – Full or mode-superposition

Substructuring (ANTYPE,SUBSTR)

Modal (ANTYPE,MODAL)

The OMEGA command supports tabular boundary conditions (%TABNAME_X%, %TABNAME_Y%, and %TABNAME_Z%) for OMEGA_X, OMEGA_Y, and OMEGA_Z input values (*DIM) for full transient and harmonic analyses.

Rotational velocities are combined with the element mass matrices to form a body force load vector term. Units are radians/time. Related commands are ACEL, CGLOC, CGOMGA, DCGOMG, and DOMEGA.

See Analysis Tools in the Mechanical APDL Theory Reference for more information.

If you have applied the Coriolis effect (CORIOLIS) using a stationary reference frame, the OMEGA command takes the gyroscopic damping matrix into account for the elements listed in the “Stationary Reference Frame” heading in the notes section of the CORIOLIS command. The element axis must pass through the global Cartesian origin. ANSYS verifies that the rotation vector axis is parallel to the axis of the element; if not, the gyroscopic effect is not applied. After issuing the OMEGA command when the Coriolis or gyroscopic effect is present, a subsequently issued CMOMEGA command has no effect.

In a mode-superposition harmonic or transient analysis, you must apply the load in the modal portion of the analysis. Mechanical APDL calculates a load vector and writes it to the MODE file, which you can apply via the LVSCALE command.

This command is also valid in PREP7.