Add a fully coupled periodic implicit operator

.github/workflows/regression.yml

@@ -233,7 +233,7 @@ jobs:
         uses: docker://ghcr.io/su2code/su2/test-su2:260405-0054
         with:
           # -t <Tutorials-branch> -c <Testcases-branch>
-          args: -b ${{github.ref}} -t develop -c develop -s ${{matrix.testscript}}
+          args: -b ${{github.ref}} -t develop -c fix_periodic_axis -s ${{matrix.testscript}}
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2:260405-0054
         with:
@@ -282,7 +282,7 @@ jobs:
         uses: docker://ghcr.io/su2code/su2/test-su2:260405-0054
         with:
           # -t <Tutorials-branch> -c <Testcases-branch>
-          args: -b ${{github.ref}} -t develop -c develop -s ${{matrix.testscript}} -a "--tapetests"
+          args: -b ${{github.ref}} -t develop -c fix_periodic_axis -s ${{matrix.testscript}} -a "--tapetests"
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2:260405-0054
         with:
@@ -330,7 +330,7 @@ jobs:
           PMIX_MCA_gds: hash
         with:
           # -t <Tutorials-branch> -c <Testcases-branch>
-          args: -b ${{github.ref}} -t develop -c develop -s ${{matrix.testscript}} -a "--tsan"
+          args: -b ${{github.ref}} -t develop -c fix_periodic_axis -s ${{matrix.testscript}} -a "--tsan"
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2-tsan:260405-0054
         with:
@@ -375,7 +375,7 @@ jobs:
         uses: docker://ghcr.io/su2code/su2/test-su2-asan:260405-0054
         with:
           # -t <Tutorials-branch> -c <Testcases-branch>
-          args: -b ${{github.ref}} -t develop -c develop -s ${{matrix.testscript}} -a "--asan"
+          args: -b ${{github.ref}} -t develop -c fix_periodic_axis -s ${{matrix.testscript}} -a "--asan"
       - name: Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2-asan:260405-0054
         with:

Common/include/geometry/CGeometry.hpp

@@ -342,8 +342,14 @@ class CGeometry {
                                               a particular vertex to be sent in periodic comms. */
       *Local_Marker_PeriodicRecv{nullptr}; /*!< \brief Data structure holding the local index of the periodic marker for
                                               a particular vertex to be received in periodic comms. */
-  su2double* bufD_PeriodicRecv{nullptr};   /*!< \brief Data structure for su2double periodic receive. */
-  su2double* bufD_PeriodicSend{nullptr};   /*!< \brief Data structure for su2double periodic send. */
+  vector<unsigned long> Local_Copy_PeriodicSend; /*!< \brief For points on a rotation axis, which are their own periodic
+                                                    match, the number of times the rotation is applied to the data
+                                                    sent (one send per other copy of the control volume). Zero for
+                                                    all other points. */
+  vector<unsigned long> Local_Copy_PeriodicRecv; /*!< \brief Same as Local_Copy_PeriodicSend, for the data received. */
+  bool PeriodicAxisPoints{false};              /*!< \brief Whether this rank has periodic points on a rotation axis. */
+  su2double* bufD_PeriodicRecv{nullptr};       /*!< \brief Data structure for su2double periodic receive. */
+  su2double* bufD_PeriodicSend{nullptr};       /*!< \brief Data structure for su2double periodic send. */
   unsigned short* bufS_PeriodicRecv{nullptr};  /*!< \brief Data structure for unsigned long periodic receive. */
   unsigned short* bufS_PeriodicSend{nullptr};  /*!< \brief Data structure for unsigned long periodic send. */
   SU2_MPI::Request* req_PeriodicSend{nullptr}; /*!< \brief Data structure for periodic send requests. */
@@ -517,6 +523,12 @@ class CGeometry {
    */
   void AllocatePeriodicComms(unsigned short val_countPerPeriodicPoint);
 
+  /*! \brief Sum partial scalar or vector geometry data over periodic copies (called by the master). */
+  void SumPeriodicGeometry(const CConfig* config, su2activematrix& values, int vectorIndex);
+
+  /*! \brief Refresh donor volumes after a mesh update. */
+  void UpdatePeriodicVolumes(const CConfig* config);
+
   /*!
    * \brief Routine to launch non-blocking recvs only for all periodic communication with neighboring partitions.
    * \note This routine is called by any class that has loaded data into the generic communication buffers.

Common/include/linear_algebra/CSysMatrix.hpp

@@ -257,6 +257,13 @@ class CSysMatrix {
  private:
   friend struct CSysMatrixComms;
 
+  int periodicVectorIndex{-2}; /*!< \brief -2 disables periodic projection; -1 denotes scalar variables. */
+  mutable CSysVector<ScalarType> projectedInput;
+  mutable su2activematrix periodicBuffer;
+
+  void ProjectPeriodic(const CSysVector<ScalarType>& input, CSysVector<ScalarType>& output, CGeometry* geometry,
+                       const CConfig* config) const;
+
   const int rank; /*!< \brief MPI Rank. */
   const int size; /*!< \brief MPI Size. */
 
@@ -700,6 +707,10 @@ class CSysMatrix {
   void ComputeLU_SGSPreconditionerBackward(CSysVector<ScalarType>& prod) const;
 
  public:
+  /*! \brief Keep all partial periodic rows and couple their matching unknowns in the product. */
+  void SetPeriodicProjection(int vectorIndex) { periodicVectorIndex = vectorIndex; }
+  bool HasPeriodicProjection() const { return periodicVectorIndex >= -1; }
+
   /*!
    * \brief Constructor of the class.
    */