update summation in FVM solver

Author: Bot-Enigma-0

SU2_CFD/include/solvers/CFVMFlowSolverBase.hpp

@@ -211,6 +211,8 @@ class CFVMFlowSolverBase : public CSolver {
    * coloring does not allow "enough" parallelism. ---*/
 
   CSysVector<su2double> EdgeFluxes; /*!< \brief Flux across each edge. */
+  CSysVector<su2double> EdgeFluxes_ij; /*!< \brief Flux across each edge ij (non-conservative). */
+  CSysVector<su2double> EdgeFluxes_ji; /*!< \brief Flux across each edge ji (non-conservative). */
 
   CNumericsSIMD* edgeNumerics = nullptr; /*!< \brief Object for edge flux computation. */
 
@@ -292,7 +294,20 @@ class CFVMFlowSolverBase : public CSolver {
     if (!ReducerStrategy) AD::EndNoSharedReading();
 
     if (ReducerStrategy) {
-      SumEdgeFluxes(geometry);
+      if (config->GetKind_Solver() == MAIN_SOLVER::RANS) {
+        for (unsigned long iPoint = 0; iPoint < nPoint; ++iPoint) {
+
+          LinSysRes.SetBlock_Zero(iPoint);
+
+          for (auto iEdge : geometry->nodes->GetEdges(iPoint)) {
+            if (iPoint == geometry->edges->GetNode(iEdge,0))
+              LinSysRes.AddBlock(iPoint, EdgeFluxes_ij.GetBlock(iEdge));
+            else
+              LinSysRes.SubtractBlock(iPoint, EdgeFluxes_ji.GetBlock(iEdge));
+          }
+        }        
+      }
+      else SumEdgeFluxes(geometry);
       if (config->GetKind_TimeIntScheme() == EULER_IMPLICIT) {
         Jacobian.SetDiagonalAsColumnSum();
       }

SU2_CFD/include/solvers/CFVMFlowSolverBase.inl

@@ -359,7 +359,11 @@ void CFVMFlowSolverBase<V, R>::HybridParallelInitialization(const CConfig& confi
     }
   }
 
-  if (ReducerStrategy) EdgeFluxes.Initialize(geometry.GetnEdge(), geometry.GetnEdge(), nVar, nullptr);
+  if (ReducerStrategy) {
+    EdgeFluxes.Initialize(geometry.GetnEdge(), geometry.GetnEdge(), nVar, nullptr);
+    EdgeFluxes_ij.Initialize(geometry.GetnEdge(), geometry.GetnEdge(), nVar, nullptr); //initializing only when solver=rans, has no effect
+    EdgeFluxes_ji.Initialize(geometry.GetnEdge(), geometry.GetnEdge(), nVar, nullptr);
+    }
 
   omp_chunk_size = computeStaticChunkSize(nPoint, omp_get_max_threads(), OMP_MAX_SIZE);
 #else