Allow filtering faces by neighboring subdomain ID in ParsedGenerateSi…

…deset (idaholab#15651)

framework/include/meshgenerators/ParsedGenerateSideset.h

@@ -45,12 +45,18 @@ class ParsedGenerateSideset : public SideSetsGeneratorBase, public FunctionParse
   /// whether to check subdomain ids when adding sides or not
   bool _check_subdomains;
 
+  /// whether to check neighbor subdomain ids when adding sides or not
+  bool _check_neighbor_subdomains;
+
   /// whether to check normals when adding sides or not
   bool _check_normal;
 
   /// A list of included subdomain ids that the side has to be part of
   std::vector<subdomain_id_type> _included_ids;
 
+  /// A list of included neighbor subdomain ids
+  std::vector<subdomain_id_type> _included_neighbor_ids;
+
   /// A normal vector that (if provided) is compared against side's normals
   Point _normal;
 

framework/src/meshgenerators/ParsedGenerateSideset.C

@@ -36,6 +36,10 @@ ParsedGenerateSideset::validParams()
   params.addParam<std::vector<subdomain_id_type>>(
       "included_subdomain_ids",
       "A set of subdomain ids whose sides will be included in the new sidesets");
+  params.addParam<std::vector<subdomain_id_type>>(
+      "included_neighbor_ids",
+      "A set of neighboring subdomain ids. A face is only added if the subdomain id of the "
+      "neighbor is in this set");
   params.addParam<Point>(
       "normal",
       Point(),
@@ -60,10 +64,14 @@ ParsedGenerateSideset::ParsedGenerateSideset(const InputParameters & parameters)
     _function(parameters.get<std::string>("combinatorial_geometry")),
     _sideset_name(getParam<BoundaryName>("new_sideset_name")),
     _check_subdomains(isParamValid("included_subdomain_ids")),
+    _check_neighbor_subdomains(isParamValid("included_neighbor_ids")),
     _check_normal(parameters.isParamSetByUser("normal")),
     _included_ids(_check_subdomains
                       ? parameters.get<std::vector<SubdomainID>>("included_subdomain_ids")
                       : std::vector<SubdomainID>()),
+    _included_neighbor_ids(_check_neighbor_subdomains
+                               ? parameters.get<std::vector<SubdomainID>>("included_neighbor_ids")
+                               : std::vector<SubdomainID>()),
     _normal(getParam<Point>("normal"))
 {
   if (typeid(_input).name() == typeid(std::unique_ptr<DistributedMesh>).name())
@@ -122,6 +130,27 @@ ParsedGenerateSideset::generate()
       const std::vector<Point> & normals = _fe_face->get_normals();
       _fe_face->reinit(elem, side);
 
+      // check if the neighboring elems subdomain is included
+      if (_check_neighbor_subdomains)
+      {
+        const Elem * neighbor = elem->neighbor_ptr(side);
+        // if the neighbor does not exist, then skip this face; we only add sidesets
+        // between existing elems if _check_neighbor_subdomains is true
+        if (!neighbor)
+          continue;
+
+        subdomain_id_type curr_neighbor_subdomain = neighbor->subdomain_id();
+        if (std::find(_included_neighbor_ids.begin(),
+                      _included_neighbor_ids.end(),
+                      curr_neighbor_subdomain) == _included_neighbor_ids.end())
+          continue;
+      }
+
+      if (_check_neighbor_subdomains &&
+          std::find(_included_neighbor_ids.begin(), _included_neighbor_ids.end(), curr_subdomain) ==
+              _included_ids.end())
+        continue;
+
       // check normal if requested
       if (_check_normal && std::abs(1.0 - _normal * normals[0]) > _variance)
         continue;

test/tests/meshgenerators/parsed_generate_sideset/parsed_generate_sideset_neighbor_sub_id.i

@@ -0,0 +1,21 @@
+[Mesh]
+  [./cmg]
+    type = CartesianMeshGenerator
+    dim = 2
+    dx = '1 1'
+    dy = '2 2'
+    subdomain_id = '0 1 0 0'
+  [../]
+
+  [sideset]
+    type = ParsedGenerateSideset
+    input = cmg
+    combinatorial_geometry = 'abs(x - 1) < 1e-6'
+    included_neighbor_ids = '1'
+    new_sideset_name = interior
+  []
+[]
+
+[Outputs]
+  exodus = true
+[]

test/tests/meshgenerators/parsed_generate_sideset/tests

@@ -11,4 +11,17 @@
     design = 'meshgenerators/ParsedGenerateSideset.md'
     issues = '#11640'
   [../]
+
+  [./parsed_generate_sideset_neighbor_sub_id_test]
+    type = 'Exodiff'
+    input = 'parsed_generate_sideset_neighbor_sub_id.i'
+    cli_args = '--mesh-only'
+    exodiff = 'parsed_generate_sideset_neighbor_sub_id_in.e'
+    mesh_mode = 'REPLICATED'
+    recover = false
+
+    requirement = 'The system shall have the ability to filter by neighboring subdomain id in ParsedGenerateSideset.'
+    design = 'meshgenerators/ParsedGenerateSideset.md'
+    issues = '#15651'
+  [../]
 []