[FLASH-USERS] Problem with applyBCEdge

[Klaus Weide]

On Tue, 1 Dec 2009, James Guillochon wrote:

> Hi all,
> 
> So I am using the Grid_applyBCEdge.F90 from the WindTunnel problem to 
> include a fixed boundary condition in my simulation (-X boundary). It 
> seems to partially work on the interface, but every other block doesn't 
> seem to be applying the boundary condition, which results in a bizarre 
> checkerboard pattern (attached to this e-mail). I think the issue must 
> be in the looping indices in the region specialized function, which I 
> have not modified. I am using FLASH 3.2, and the problem exists with the 
> default ppm4 and ppm4dev. Any ideas? The attached image shows a slice 
> through the grid cells just interior to the boundary cells.

James,

The checkerboard pattern looks quite ... interesting, but without more 
information about the context it it hard to interpret.  Are those 
checkerboard squares cells or blocks?  Are you showing one block
or the whole domain? (Are they actually the same thing?) How many time
steps does it take for this pattern to develop?

One very basic thing to check: since you took the Grid_applyBCEdge.F90 
form the WindTunnel simulation, make sure you have also copied relevant 
lines from the Config file.  In paricular, you should have copied the
following line from WindTunnel's Config:

 REQUIRES Grid/GridBoundaryConditions/OneRow

Let me know if this helps!

Klaus