Prescribed Velocity
The Prescribed Velocity node adds an edge, boundary, or domain condition where the translational or rotational velocity is prescribed in one or more directions. The prescribed velocity condition is applicable for Time Dependent and Frequency Domain studies. With this condition it is possible to prescribe a velocity in one direction, leaving the shell free in the other directions.
The Prescribed Velocity node is a constraint, and overrides any other constraint on the same selection.
Coordinate System Selection
Specify the coordinate system to use for specifying the prescribed velocity. The components are entered in the selected coordinate system.
The coordinate system selection is based on the geometric entity level.
Domains (Plate interface)
From the Coordinate system list select from:
Boundaries (Shell and Plate interfaces)
From the Coordinate system list select from:
Boundary System (a predefined normal-tangential coordinate system)
Edges (Shell interface)
From the Coordinate system list select from:
Global coordinate system (the standard global coordinate system).
Local edge system (the default)
Face Defining the Local Orientations
This setting is used in conjunction with a Local edge system and Shell Local System. If the velocity is prescribed for an edge which is shared between boundaries, the edge system can be ambiguous. Select the boundary which should define the edge system. The default is Use face with lowest number.
Prescribed Velocity
To define a prescribed velocity for each spatial direction (x, y, and z), select one or more of the Prescribed in x direction, Prescribed in y direction, and Prescribed in z direction check boxes. Then enter a value or expression for the prescribed velocity components vx, vy, and vz.
Prescribed Angular Velocity
To define a prescribed angular velocity for each spatial direction (x, y, and z), select one or all of the Prescribed around x direction, Prescribed around y direction, and Prescribed around z direction check boxes and enter a value or expression for in each , , or field.
You can add a Harmonic Perturbation subnode for specifying a harmonic variation of the values of the prescribed velocity in a frequency domain analysis of perturbation type.
Prescribed Velocity can not be used as a weak constraint.
Location in User Interface
Context Menus
Shell>Face Constraints>Prescribed Velocity
Shell>More Constraints>Prescribed Velocity (Edge)
Plate>Face Constraints>Prescribed Velocity
Plate>More Constraints>Prescribed Velocity (Boundary)
Ribbon
Physics tab with Shell selected:
Boundaries>Face Constraints>Prescribed Velocity
Edges>>More Constraints>Prescribed Velocity
Physics tab with Plate selected:
Domains>Face Constraints>Prescribed Velocity
Boundaries>>More Constraints>Prescribed Velocity