Flip fresh

framework/doc/content/source/meshgenerators/FlipSidesetGenerator.md

@@ -0,0 +1,14 @@
+# FlipSidesetGenerator
+
+!syntax description /Mesh/FlipSidesetGenerator
+
+## Overview
+
+The `FlipSidesetGenerator` object flips the normal of a sideset by changing the element the sideset is attached to. 
+The sideset cannot be flipped if the original element it is attached to does not have a neighbor through the sideset. 
+
+!syntax parameters /Mesh/FlipSidesetGenerator
+
+!syntax inputs /Mesh/FlipSidesetGenerator
+
+!syntax children /Mesh/FlipSidesetGenerator

framework/include/meshgenerators/FlipSidesetGenerator.h

@@ -0,0 +1,33 @@
+//* This file is part of the MOOSE framework
+//* https://www.mooseframework.org
+//*
+//* All rights reserved, see COPYRIGHT for full restrictions
+//* https://github.com/idaholab/moose/blob/master/COPYRIGHT
+//*
+//* Licensed under LGPL 2.1, please see LICENSE for details
+//* https://www.gnu.org/licenses/lgpl-2.1.html
+
+#pragma once
+
+#include "MeshGenerator.h"
+
+/**
+ * MeshGenerator for flipping a sideset
+ */
+class FlipSidesetGenerator : public MeshGenerator
+{
+public:
+  static InputParameters validParams();
+
+  FlipSidesetGenerator(const InputParameters & parameters);
+
+protected:
+  std::unique_ptr<MeshBase> generate() override;
+
+private:
+  /// Input mesh the operation will be applied to
+  std::unique_ptr<MeshBase> & _input;
+
+  /// Name of the sideset to flip
+  const BoundaryName _sideset_name;
+};

framework/src/meshgenerators/FlipSidesetGenerator.C

@@ -0,0 +1,72 @@
+//* This file is part of the MOOSE framework
+//* https://www.mooseframework.org
+//*
+//* All rights reserved, see COPYRIGHT for full restrictions
+//* https://github.com/idaholab/moose/blob/master/COPYRIGHT
+//*
+//* Licensed under LGPL 2.1, please see LICENSE for details
+//* https://www.gnu.org/licenses/lgpl-2.1.html
+
+#include "FlipSidesetGenerator.h"
+
+#include "CastUniquePointer.h"
+
+registerMooseObject("MooseApp", FlipSidesetGenerator);
+
+InputParameters
+FlipSidesetGenerator::validParams()
+{
+  InputParameters params = MeshGenerator::validParams();
+  params.addClassDescription("A Mesh Generator which flips a given sideset");
+  params.addRequiredParam<MeshGeneratorName>("input", "The mesh we want to modify");
+  params.addRequiredParam<BoundaryName>("boundary", "The sideset (boundary) that will be flipped");
+  return params;
+}
+
+FlipSidesetGenerator::FlipSidesetGenerator(const InputParameters & parameters)
+  : MeshGenerator(parameters),
+    _input(getMesh("input")),
+    _sideset_name(getParam<BoundaryName>("boundary"))
+{
+}
+
+std::unique_ptr<MeshBase>
+FlipSidesetGenerator::generate()
+{
+  // get boundary info
+  BoundaryInfo & boundary_info = _input->get_boundary_info();
+  // get id of the input sideset
+  const auto sideset_id = boundary_info.get_id_by_name(_sideset_name);
+
+  // Throw an error if the sideset doesn't exist
+  if (sideset_id == libMesh::BoundaryInfo::invalid_id)
+    paramError("boundary", "The boundary '", _sideset_name, "' was not found");
+
+  // get a copy of sideset map to avoid changing the sideset map while looping on it
+  std::multimap<const Elem *, std::pair<unsigned short int, boundary_id_type>> sideset_map =
+      boundary_info.get_sideset_map();
+
+  // old_elem is the original element attached to the sideset before flipping
+  // new_elem is the element attached to the sideset after flipping
+  for (const auto & [old_elem, id_pair] : sideset_map)
+  {
+    boundary_id_type boundary_id = std::get<1>(id_pair);
+    if (boundary_id == sideset_id)
+    {
+      const auto old_side_id = std::get<0>(id_pair);
+      const auto old_elem_id = old_elem->id();
+      const auto new_elem = old_elem->neighbor_ptr(old_side_id);
+
+      // Throw an error if the old element doesn't have a neighbor on the old side
+      if (!new_elem)
+        mooseError("elem " + std::to_string(old_elem_id) +
+                   " does not have a neighbor through side " + std::to_string(old_side_id) +
+                   " therefore it cannot be flipped");
+
+      const auto new_side_id = new_elem->which_neighbor_am_i(old_elem);
+      boundary_info.remove_side(old_elem, old_side_id, sideset_id);
+      boundary_info.add_side(new_elem, new_side_id, sideset_id);
+    }
+  }
+  return dynamic_pointer_cast<MeshBase>(_input);
+}

test/tests/meshgenerators/flip_sideset_generator/flux_flip_2D.i

@@ -0,0 +1,97 @@
+[Mesh]
+    [gmg]
+        type = GeneratedMeshGenerator
+        dim = 2
+        nx = 3
+        ny = 3
+        xmax = 3
+        ymax = 3
+    []
+    [s1]
+        type = ParsedGenerateSideset
+        input = gmg
+        combinatorial_geometry = 'x > 0.9 & x < 1.1 & y > -0.1 & y < 1.1'
+        normal = '1 0 0'
+        new_sideset_name = s1
+    []
+    [s2]
+        type = ParsedGenerateSideset
+        input = s1
+        combinatorial_geometry = 'x > 0.9 & x < 2.1 & y > 0.9 & y < 1.1'
+        normal = '0 1 0'
+        new_sideset_name = s2
+    []
+    [s3]
+        type = ParsedGenerateSideset
+        input = s2
+        combinatorial_geometry = 'x > 1.9 & x < 2.1 & y > 0.9 & y < 2.1'
+        normal = '1 0 0'
+        new_sideset_name = s3
+    []
+    [s4]
+        type = ParsedGenerateSideset
+        input = s3
+        combinatorial_geometry = 'x > 1.9 & x < 3.1 & y > 1.9 & y < 2.1'
+        normal = '0 1 0'
+        new_sideset_name = s4
+    []
+    [sideset]
+        type = SideSetsFromBoundingBoxGenerator
+        input = s4
+        bottom_left = '0 0 0'
+        top_right = '3 3 3'
+        boundaries_old = 's1 s2 s3 s4'
+        boundary_new = 's_combined'
+    []
+    [flip]
+        type = FlipSidesetGenerator
+        input = sideset
+        boundary = s_combined
+    []
+[]
+
+[AuxVariables]
+    [u]
+    []
+[]
+
+[AuxKernels]
+    [diffusion]
+        type = FunctionAux
+        variable = u
+        function = func
+    []
+[]
+
+[Functions]
+    [func]
+        type = ParsedFunction
+        expression = x+y
+    []
+[]
+
+[Problem]
+    type = FEProblem
+    solve = false
+[]
+
+[Postprocessors]
+    [flux]
+        type = SideDiffusiveFluxIntegral
+        variable = u
+        boundary = s_combined
+        diffusivity = 1
+    []
+    [area]
+        type = AreaPostprocessor
+        boundary = s_combined
+    []
+[]
+
+[Executioner]
+    type = Steady
+[]
+
+[Outputs]
+    csv = true
+[]

test/tests/meshgenerators/flip_sideset_generator/flux_flip_3D.i

@@ -0,0 +1,76 @@
+[Mesh]
+  [gmg]
+    type = GeneratedMeshGenerator
+    dim = 3
+    nx = 3
+    ny = 3
+    nz = 3
+    xmax = 3
+    ymax = 3
+    zmax = 3
+  []
+  [subdomains]
+    type = ParsedSubdomainMeshGenerator
+    input = gmg
+    combinatorial_geometry = 'x < 1 & y > 1 & y < 2'
+    block_id = 1
+  []
+  [sideset]
+    type = ParsedGenerateSideset
+    input = subdomains
+    combinatorial_geometry = 'z < 1'
+    included_subdomains = '1'
+    normal = '1 0 0'
+    new_sideset_name = interior
+  []
+  [flip]
+    type = FlipSidesetGenerator
+    input = sideset
+    boundary = interior
+  []
+[]
+[AuxVariables]
+    [u]
+    []
+[]
+
+[AuxKernels]
+    [diffusion]
+        type = FunctionAux
+        variable = u
+        function = func
+    []
+[]
+
+[Functions]
+    [func]
+        type = ParsedFunction
+        expression = x+y+z
+    []
+[]
+
+[Problem]
+    type = FEProblem
+    solve = false
+[]
+
+[Postprocessors]
+    [flux]
+        type = SideDiffusiveFluxIntegral
+        variable = u
+        boundary = interior
+        diffusivity = 1
+    []
+    [area]
+        type = AreaPostprocessor
+        boundary = interior
+    []
+[]
+
+[Executioner]
+    type = Steady
+[]
+
+[Outputs]
+    csv = true
+[]

test/tests/meshgenerators/flip_sideset_generator/gold/flux_flip_2D_out.csv

@@ -0,0 +1,3 @@
+time,area,flux
+0,0,0
+1,4,4

test/tests/meshgenerators/flip_sideset_generator/gold/flux_flip_3D_out.csv

@@ -0,0 +1,3 @@
+time,area,flux
+0,0,0
+1,1,1

test/tests/meshgenerators/flip_sideset_generator/no_neighbor.i

@@ -0,0 +1,16 @@
+[Mesh]
+    [gmg]
+        type = GeneratedMeshGenerator
+        dim = 2
+        nx = 1
+        ny = 1
+    []
+    [flip]
+        type = FlipSidesetGenerator
+        input = gmg
+        boundary = 'right'
+    []
+[]
+[Outputs]
+    exodus = true
+[]

test/tests/meshgenerators/flip_sideset_generator/no_sideset.i

@@ -0,0 +1,16 @@
+[Mesh]
+    [gmg]
+        type = GeneratedMeshGenerator
+        dim = 2
+        nx = 1
+        ny = 1
+    []
+    [flip]
+        type = FlipSidesetGenerator
+        input = gmg
+        boundary = 'bad_side'
+    []
+[]
+[Outputs]
+    exodus = true
+[]

test/tests/meshgenerators/flip_sideset_generator/tests

@@ -0,0 +1,39 @@
+[Tests]
+  issues = '#25528'
+  design = 'FlipSidesetGenerator.md'
+  [flux_2D]
+    type = 'CSVDiff'
+    input = 'flux_flip_2D.i'
+    csvdiff = 'flux_flip_2D_out.csv'
+    recover = false
+    requirement = 'The system shall support switching the normal orientation of a sideset in a two-dimensional mesh'
+    mesh_mode = 'replicated'
+  []
+
+  [flux_3D]
+    type = 'CSVDiff'
+    input = 'flux_flip_3D.i'
+    csvdiff = 'flux_flip_3D_out.csv'
+    recover = false
+    requirement = 'The system shall support switching the normal orientation of a sideset in a three-dimensional mesh'
+    mesh_mode = 'replicated'
+  []
+
+  [no_sideset_exception]
+    type = 'RunException'
+    input = 'no_sideset.i'
+    cli_args = '--mesh-only'
+    expect_err = "The boundary 'bad_side' was not found"
+    requirement = "The system shall produce a reasonable error when switching the normal orientation of a sideset if the sideset does not exist"
+    mesh_mode = 'replicated'
+  []
+
+  [no_neighbor_exception]
+    type = 'RunException'
+    input = 'no_neighbor.i'
+    cli_args = '--mesh-only'
+    expect_err = "elem 0 does not have a neighbor through side 1 therefore it cannot be flipped"
+    requirement = "The system shall produce a reasonable error when switching the normal orientation of a sideset if the sideset cannot be flipped"
+    mesh_mode = 'replicated'
+  []
+[]