ghostwidth
The parameter ghostwidth only has an effect is parameter
allowedl > 0. This parameter indicates the number of taper points
in the AMR algorithm. Note that it does not control the number
of ghostzones; parameter bound_width does that.
The idea of ghostwidth is to set it so that,
using Method of Lines integration, points in the interior (that is more
than ghostwidth points from the boundary) should be causally
disconnected from the subgrid boundary.
For a refinement ratio of 2:1 and Runge Kutta 3rd order integration, ghostwidth
should be 6. If the user changes the order of time integration or the
refinement factor ( controlled through parameter refine_factor ),
ghostwidth would also have to be modified accordingly.
Notes
- Parameter ghostwidth is an AMR parameter and does not
control the number of communicated points across interprocessor
boundaries; parameter bound_width does that.
- ghostwidth = 6 is the correct choice for
RK3 time integration and refine_factor = 2. Altering either
of those choices requires modifying the ghostwidth size.
- For a typical Runge Kutta 3rd order integration:
- amrbound_prepost := 1
- amrbound_timealign := 0
- ghostwidth := 6
- For a typical iterative Crank Nicholson integration:
- amrbound_prepost := 0
- amrbound_timealign := 1
- ghostwidth := 1
See Also
bound_width,
refine_factor,
runge_kutta_type,
amrbound_prepost,
amrbound_timealign
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Examples
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