Added min-max safety on weights

src/finiteVolume/fields/fvPatchFields/constraint/regionCoupling/regionCouplingFvPatchField.C

@@ -185,7 +185,7 @@ regionCouplingFvPatchField<Type>::shadowPatchField() const
 }
 
 
-// Return neighbour field given internal cell data
+// Return neighbour field
 template<class Type>
 tmp<Field<Type> > regionCouplingFvPatchField<Type>::patchNeighbourField() const
 {
@@ -238,7 +238,6 @@ tmp<Field<Type> > regionCouplingFvPatchField<Type>::patchNeighbourField
 }
 
 
-
 template<class Type>
 void regionCouplingFvPatchField<Type>::initEvaluate
 (
@@ -288,7 +287,9 @@ void regionCouplingFvPatchField<Type>::initEvaluate
         // HJ, 28/Sep/2011
         if (mag(den) > kSmall)
         {
-            weights[faceI] = (mNei[faceI] - mean[faceI])/den;
+            // Limit weights for round-off safety
+            weights[faceI] =
+                Foam::max(0, Foam::min((mNei[faceI] - mean[faceI])/den, 1));
         }
         else
         {
@@ -340,7 +341,9 @@ void regionCouplingFvPatchField<Type>::initEvaluate
                     pDeltaCoeffs[faceI]
                 );
 
-            weights[faceI] = (magPhiNei[faceI] - mean)/den;
+            // Limit weights for round-off safety
+            weights[faceI] =
+                Foam::max(0, Foam::min((magPhiNei[faceI] - mean)/den, 1));
         }
         else
         {
@@ -410,6 +413,8 @@ void regionCouplingFvPatchField<Type>::initInterfaceMatrixUpdate
     const direction cmpt,
     const Pstream::commsTypes
 ) const
+{
+    if (regionCouplePatch_.coupled())
     {
         // Prepare local matrix update buffer for the remote side.
         // Note that only remote side will have access to its psiInternal
@@ -423,6 +428,16 @@ void regionCouplingFvPatchField<Type>::initInterfaceMatrixUpdate
                 this->patch().patchInternalField(psiInternal)
             );
     }
+    else
+    {
+        FatalErrorIn
+        (
+            "regionCouplingFvPatchField<Type>::initInterfaceMatrixUpdate"
+        )   << "init matrix update calld in detached state"
+            << abort(FatalError);
+
+    }
+}
 
 
 // Return matrix product for coupled boundary
@@ -436,6 +451,8 @@ void regionCouplingFvPatchField<Type>::updateInterfaceMatrix
     const direction ,
     const Pstream::commsTypes
 ) const
+{
+    if (regionCouplePatch_.coupled())
     {
         // Note: interpolation involves parallel communications and needs to
         // happen during init.  This changes the use of matrix update buffer
@@ -451,6 +468,16 @@ void regionCouplingFvPatchField<Type>::updateInterfaceMatrix
             result[fc[elemI]] -= coeffs[elemI]*pnf[elemI];
         }
     }
+    else
+    {
+        FatalErrorIn
+        (
+            "regionCouplingFvPatchField<Type>::updateInterfaceMatrix"
+        )   << "Matrix update calld in detached state"
+            << abort(FatalError);
+
+    }
+}
 
 
 // Write

src/finiteVolume/interpolation/surfaceInterpolation/schemes/harmonic/harmonic.H

@@ -162,8 +162,9 @@ public:
                 // HJ, 28/Sep/2011
                 if (mag(den) > kSmall)
                 {
-                    // mOwn > mNei
+                    // Limit weights for round-off safety
-                    wIn[faceI] = (magPhi[nei] - mean)/den;
+                    wIn[faceI] =
+                        Foam::max(0, Foam::min((magPhi[nei] - mean)/den, 1));
                 }
                 else
                 {
@@ -209,7 +210,17 @@ public:
                                     pDeltaCoeffs[faceI]
                                 );
 
-                            wp[faceI] = (magPhiNei[faceI] - mean)/den;
+                            // Limit weights for round-off safety
+                            wp[faceI] =
+                                Foam::max
+                                (
+                                    0,
+                                    Foam::min
+                                    (
+                                        (magPhi[faceI] - mean)/den,
+                                        1
+                                    )
+                                );
                         }
                         else
                         {