bendudson / BOUT

NOTE: BOUT++ now at https://github.com/boutproject/BOUT-dev
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Changing width of boundary region #27

Closed bendudson closed 11 years ago

bendudson commented 13 years ago

It's often useful to adjust the width of boundary regions for individual variables. For example it's often useful to damp jparallel near the boundaries. When using shifted grids, boundaries need to be applied at different points for shifted and non-shifted variables.

A mechanism is needed to change the boundary width for each variable on each boundary separately. Probably easiest as a boundary modifier, so in BOUT.inp:

bndry_xin = width(neumann, 5)

would modify a Neumann boundary condition to have a width of 5 on the inner X boundary.