[cig-commits] [commit] master: Address Timo's review comments. (7989f00)

[cig_noreply at geodynamics.org]

Repository : https://github.com/geodynamics/aspect

On branch  : master
Link       : https://github.com/geodynamics/aspect/compare/3811725812cafa918bbabc2515f52af7857aad31...9a8086507e7ed22ed2a4d13771930e4ae6bc3a7d

>---------------------------------------------------------------

commit 7989f004ff45998704c20730d196568435df70d5
Author: Wolfgang Bangerth <bangerth at math.tamu.edu>
Date:   Wed Jul 30 11:10:12 2014 -0500

    Address Timo's review comments.


>---------------------------------------------------------------

7989f004ff45998704c20730d196568435df70d5
 source/geometry_model/spherical_shell.cc     | 32 ++++++++++++++++++++++------
 source/initial_conditions/spherical_shell.cc |  4 ++--
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/source/geometry_model/spherical_shell.cc b/source/geometry_model/spherical_shell.cc
index c37cee7..4b4edf8 100644
--- a/source/geometry_model/spherical_shell.cc
+++ b/source/geometry_model/spherical_shell.cc
@@ -42,7 +42,15 @@ namespace aspect
                                       Point<dim>(),
                                       R0,
                                       R1,
-                                      (dim==3) ? 8*n_cells_along_circumference : n_cells_along_circumference,
+                                      (n_cells_along_circumference == 0
+				       ?
+				       // automatic choice that leads to reasonable
+				       // meshes with the typical aspect ratio of
+				       // the Earth
+				       (dim==3 ? 96 : 12)
+				       :
+				       // user choice
+				       n_cells_along_circumference),
                                       true);
         }
       else if (phi == 90)
@@ -187,12 +195,24 @@ namespace aspect
                              "Opening angle in degrees of the section of the shell "
                              "that we want to build. Units: degrees.");
 
-          prm.declare_entry ("Cells along circumference", "12",
-                             Patterns::Integer (),
+          prm.declare_entry ("Cells along circumference", "0",
+                             Patterns::Integer (0),
                              "The number of cells in circumferential direction that are "
-                             "created in the coarse mesh in 2d. In 3d, the number of "
-                             "cells is computed differently and does not have an "
-                             "easy interpretation. It is best left at its default in 3d.");
+                             "created in the coarse mesh in 2d. If zero, this number "
+			     "is chosen automatically in a way that produces meshes "
+			     "in which cells have a reasonable aspect ratio for models "
+			     "in which the depth of the mantle is roughly that of the "
+			     "Earth. For planets with much shallower mantles and larger "
+			     "cores, you may want to chose a larger number to avoid "
+			     "cells that are elongated in tangential and compressed in "
+			     "radial direction."
+			     "\n\n"
+			     "In 3d, the number of cells is computed differently and does "
+			     "not have an easy interpretation. Valid values for this parameter "
+			     "in 3d are 0 (let this class choose), 6, 12 and 96. "
+			     "Other possible values may be discussed in the documentation "
+			     "of the deal.II function GridGenerator::hyper_shell. "
+			     "The parameter is best left at its default in 3d.");
         }
         prm.leave_subsection();
       }
diff --git a/source/initial_conditions/spherical_shell.cc b/source/initial_conditions/spherical_shell.cc
index 657f001..e264ded 100644
--- a/source/initial_conditions/spherical_shell.cc
+++ b/source/initial_conditions/spherical_shell.cc
@@ -276,8 +276,8 @@ namespace aspect
                                        "An initial temperature field in which the temperature "
                                        "is perturbed following an $N$-fold pattern in a specified "
                                        "direction from an otherwise spherically symmetric "
-                                       "state. The class's name comes from previous versions"
-                                       "when the only opiton was $N=6$.")
+                                       "state. The class's name comes from previous versions "
+                                       "when the only option was $N=6$.")
 
     ASPECT_REGISTER_INITIAL_CONDITIONS(SphericalGaussianPerturbation,
                                        "spherical gaussian perturbation",