Nonorthogonal with minimal differential operators MMS test.

.pip_install_for_tests.sh

@@ -19,6 +19,12 @@ do
     fi
 done
 
+# Install xBOUT to make sure we get master version
+git clone https://github.com/boutproject/xBOUT.git
+cd xBOUT
+pip3 install --user .
+cd ..
+
 # Install Hermes-3
 git clone https://github.com/boutproject/xhermes.git
 cd xhermes

CMakeLists.txt

@@ -245,6 +245,29 @@ if(HERMES_TESTS)
     add_test(NAME hermes_unit_tests COMMAND hermes_unit_tests)
     target_link_libraries(hermes_unit_tests PRIVATE gtest bout++::bout++ hermes-3-lib)
   endif()
+
+# Method of manufactured solutions (MMS) tests
+  option(HERMES_DIVOPS_MMS_TESTS "Build the differential operator MMS tests" ON)
+  if(HERMES_DIVOPS_MMS_TESTS)
+    if(NOT PACKAGE_TESTS)
+      # Not running BOUT++ tests
+      # Since BOUT++ includes googletest, adding it again causes errors
+      set(CMAKE_CXX_STANDARD 14) # Needed to compile GoogleTest on Darwin
+      # add_subdirectory(external/googletestmms)
+    endif()
+    file(GLOB_RECURSE TEST_SOURCES tests/mms/test_*.cxx)
+
+    add_executable(hermes_mms_tests
+                   tests/mms/main.cxx
+                   ${TEST_SOURCES})
+    target_link_libraries(hermes_mms_tests PRIVATE gtest bout++::bout++ hermes-3-lib)
+    add_test(NAME differential_operators_mms_orthogonal
+           WORKING_DIRECTORY tests/mms/
+           COMMAND python3 orthogonal_test.py)
+    add_test(NAME differential_operators_mms_nonorthogonal
+           WORKING_DIRECTORY tests/mms/
+           COMMAND python3 nonorthogonal_test.py)
+  endif()
 endif()
 
 # Compile-time options

include/div_ops.hxx

@@ -69,6 +69,15 @@ const Field3D Div_a_Grad_perp_upwind_flows(const Field3D& a, const Field3D& f, F
 const Field3D Div_par_K_Grad_par_mod(const Field3D& k, const Field3D& f, Field3D& flow_ylow,
                                      bool bndry_flux = true);
 
+/*!
+ * Div ( a Grad_perp(f) ) -- ∇⊥ ( a ⋅ ∇⊥ f) -- Vorticity
+ *
+ * This version includes corrections for non-orthogonal meshes
+ * in which the g12 and g13 components can be non-zero
+ * i.e. X-Y, X-Z and Y-Z coordinates can all be non-orthogonal.
+ */
+Field3D Div_a_Grad_perp_nonorthog(const Field3D& a, const Field3D& x);
+
 namespace FV {
 
 /// Superbee limiter