ADMBase: evolving with evolution_method="static" does not apply boundary conditions

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Issue #365 closed
Erik Schnetter created an issue

When one uses the evolution method ADMBASE::evolution_method = "static" (which is very tempting e.g. for Cowling), then no boundary conditions are applied. This means that the ADMBase variables remain unset on the boundaries after regridding, leading to all sorts of (rather unexpected) problems.

The easy solution is to use thorn Exact instead, which applies an exact solution at each time step, including on the boundary.

I suggest to remove the ADMBase functionality to provide a "static" evolution method, since this evolution method does not know which boundary condition to apply, and hence is bound to fail in non-trivial situations. Alternatively, ADMBase needs to synchronise in postregrid (and probably a few other bins as well). ADMBase should then also offer to apply an outer boundary condition, in this case probably a Minkowski Dirichlet boundary condition or a von Neumann condition.

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Comments (5)

  1. Roland Haas
    • removed comment

    A third option (I think) might be to re-initialize the grid functions (using the same routines that were used in INITIAL) in all the postregrid bins (for the static evolution method only). Since the solution is "static" it should still be the same that it was at t=0. Then one does not have to worry about boundary conditions, boundary selections, SYNC. This is then somewhat close to what Exact does.

  2. Erik Schnetter reporter
    • changed status to open
    • removed comment

    While this is a duplicate, there is some discussion and some new ideas in this ticket which are for all practical purposes lost if a ticket is closed like this.

  3. Roland Haas
    • changed status to resolved
    • removed comment

    Ticket was closed as duplicate. Issue no longer exists (duplicate ticket is marked fixed). Closing ticket to clear backlog queue :-).

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