I am trying to setup a simple simulation using CarpetRegrid2's AMR capability. As Erik has already pointed out to me (off list), the adaptive-refinement triggering code is still under development. Nevertheless, I would really like to get it working.
In my current test case, I am using Kranc to solve a Klein-Gordon equation (with a non-linear potential). With the provided initial conditions, the system has an expanding bubble. This works well when refinement is turned off. To be clear, the evolution equation is:
evolCalc = { Name -> "SFBubble_Evolve", Schedule -> {"in MoL_CalcRHS"}, Where -> Interior, Shorthands -> {}, Equations -> { dot[chi] -> chiM, dot[chiM] -> PD[chi,li,lj] Euc[ui,uj] - Vchi[chi] } };
where Vchi[chi_] := V'[chi] (V is the potential). The AMR level_mask is set by:
lvlmskSet = { Name -> "SFBubble_SetLevelMask", Schedule -> {"AT preregrid"}, Where -> Interior, Shorthands -> { adchix, adchiy, adchiz }, Equations -> { adchix -> fabs[dx PD[chi,1]], adchiy -> fabs[dy PD[chi,2]], adchiz -> fabs[dz PD[chi,3]],
"level_mask" -> ( Max[ adchix, adchiy, adchiz ]/dchimax ) /. Max[a_, b_, c_] -> fmax[a, fmax[b, c]] } };
(in words: the value of chi should not change by more than dchimax over the length of one grid cell)
I am using the Periodic thorn to provide periodic boundary conditions.
I've attached six pictures. They are at t = 0, the first level 1 intermediate time step, and the first coarse time step. The first three pictures are the value of chi on a slice through the middle of the box. The second three pictures are the value of level_mask. As can be seen in the second chi image, the interpolation into the refined region seems to be incorrect. The "boundary" seems to have appeared in the middle of the block. I have also attached the block descriptions. Is there something I could be doing incorrectly which would cause this? Otherwise, does anyone have any ideas on where to look for the problem?
I am using the trunk version as of this morning.
Thank you in advance, Hal
