1: Split/merge AMR and conservative remapping

docs/source/changelog.rst

@@ -49,6 +49,18 @@ Additional controls are available for TDC envelope remeshing:
 - ``TDC_hydro_nz_inner`` adds geometrically spaced zones near the inner boundary.
 - ``TDC_hydro_nz_T_gradient`` adds zones according to the variation in ``logT`` below ``TDC_hydro_T_anchor`` while retaining the mass-based mesh.
 
+Metric zoning for split/merge AMR now uses ``split_merge_amr_MaxLong`` both
+to split an existing oversized cell and to reject a proposed merge whose
+summed metric would exceed the same limit. This removes the redundant metric
+merge-guard control and keeps the prospective merge and subsequent split
+criteria consistent.
+
+The optional pressure-child reconstruction for cell-centered split/merge AMR
+now includes MLT turbulent pressure in its bounded pressure target. The
+conservative energy transfer continues to modify only the EOS pressure; the
+turbulent contribution is evaluated from its remapped face state. Split/merge
+AMR does not currently support RSP2.
+
 .. _Bug Fixes main:
 
 Bug Fixes

star/defaults/controls.defaults

@@ -6018,6 +6018,7 @@
       ! ~~~~~~~~~~~~~
 
       ! Limit on difference in lnR across cell for mesh refinement.
+      ! Applies to standard and split/merge AMR mesh refinement.
       ! Do not make this smaller than about 1d-14 or will fail with numerical problems.
 
       ! ::
@@ -6028,7 +6029,8 @@
       ! merge_if_dlnR_too_small
       ! ~~~~~~~~~~~~~~~~~~~~~~~
 
-      ! If true, mesh adjustment will force merge if difference in lnR across cell is too small.
+      ! If true, standard and split/merge AMR mesh adjustment will force merge
+      ! if difference in lnR across cell is too small.
 
       ! ::
 
@@ -6094,7 +6096,8 @@
       ! min_surface_cell_dq
       ! ~~~~~~~~~~~~~~~~~~~
 
-      ! Largest allowed dq at surface.
+      ! Largest and smallest allowed dq at the surface.
+      ! ``min_surface_cell_dq`` also applies to split/merge AMR.
 
       ! ::
 
@@ -6723,7 +6726,9 @@
       ! ~~~~~~~~~~~~~~~~~~~~~~~~
 
       ! split cell if ratio of actual/desired size is > split_merge_amr_MaxLong; ignore if <= 0
-      ! merge cell if ratio of desired/actual size is < split_merge_amr_MaxShort; ignore if <= 0
+      ! for metric zoning, also reject a proposed merge if the summed metric of
+      ! the resulting cell exceeds split_merge_amr_MaxLong times the target size.
+      ! merge cell if ratio of desired/actual size is > split_merge_amr_MaxShort; ignore if <= 0
       ! be careful to avoid inconsistent limits such as when a required split triggers a required merge.
       ! to be safe, make sure product of limits > 2.
 

star/defaults/controls_dev.defaults

@@ -283,3 +283,75 @@
       ! ::
 
     use_hydro_merge_limits_in_mesh_plan = .false.
+
+
+      ! split_merge_amr_use_metric_zoning_for_u_flag
+      ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+      ! If true, and ``use_split_merge_amr`` and ``u_flag`` are true, use the
+      ! weighted split/merge metric controls below instead of the standard
+      ! single-coordinate split/merge zoning controls.  This is ignored for
+      ! ``v_flag``.
+
+      ! ::
+
+    split_merge_amr_use_metric_zoning_for_u_flag = .false.
+
+
+      ! split_merge_amr_metric_logR_weight
+      ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+      ! Weight for the normalized log radius contribution in the ``u_flag``
+      ! split/merge metric.
+
+      ! ::
+
+    split_merge_amr_metric_logR_weight = 1d0
+
+
+      ! split_merge_amr_metric_logtau_weight
+      ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+      ! Weight for the normalized log optical-depth contribution in the
+      ! ``u_flag`` split/merge metric.
+
+      ! ::
+
+    split_merge_amr_metric_logtau_weight = 1d0
+
+
+      ! split_merge_amr_metric_min_delta_lnR
+      ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+      ! Floor for the log radius normalization range in the ``u_flag``
+      ! split/merge metric.
+
+      ! ::
+
+    split_merge_amr_metric_min_delta_lnR = 1d-9
+
+
+      ! split_merge_amr_metric_min_delta_lntau
+      ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+      ! Floor for the log optical-depth normalization range in the ``u_flag``
+      ! split/merge metric.
+
+      ! ::
+
+    split_merge_amr_metric_min_delta_lntau = 1d-9
+
+
+      ! split_merge_amr_reconstruct_pressure_for_u_flag
+      ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+      ! If true, redistribute internal energy between the children of an
+      ! ``u_flag`` split to preserve the limited pre-split pressure gradient.
+      ! The correction preserves total child internal energy and falls back to
+      ! the standard conservative split when no bounded EOS solution exists.
+      ! The pressure target includes MLT turbulent pressure. Split/merge AMR
+      ! does not currently support RSP2.
+
+      ! ::
+
+    split_merge_amr_reconstruct_pressure_for_u_flag = .false.