OOF2: The Manual
Name
Periodic (PeriodicBC) — Set the values of a field to be equal along two opposite boundaries.
Synopsis
PeriodicBC
(field
,equation
,boundary
)
Description
Periodic boundary conditions set the values of a component of a Field
on a
periodic pair of exterior edge boundaries to
be the same. A separate boundary condition must be established for each
component of a Field
that is to be periodic. The value for the
boundary
parameter must be a string containing the names
of two boundaries that constitute a periodic pair: the appropriate periodicity option
must have been chosen when the skeleton was created in the skeleton task page and the
directions of the boundaries must be opposite. By default, the left and
right boundaries will constitute a valid pair if
left_right_periodicity
was chosen when the skeleton is
created, as will the top and bottom boundaries, if
top_bottom_periodity
was chosen. The GUI presents a pull
down menu listing the legal strings, but users of the text interface will
need to know the possible values.
The field
, field_component
,
equation
, and eqn_component
parameters
are the same as those for Dirichlet boundary conditions.
See that discussion for details. Note that periodic boundary conditions do
not have a profile
parameter.
Example.
PeriodicBC(field=Displacement, field_component='y', equation=Force_Balance, eqn_component='y', boundary='left right')
This constrains the y component of the
Displacement
along the right and left boundaries of
the Mesh
, making the y component of the
Force_Balance
periodic in the horizontal direction.