BUG: fixedNormalSlip BC: add 'value' keyword (#1980,#1981)

DOC: improve header-file content

Co-authored-by: Kutalmis Bercin <kutalmis.bercin@esi-group.com>

src/finiteVolume/fields/fvPatchFields/derived/fixedNormalSlip/fixedNormalSlipFvPatchField.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2020 OpenCFD Ltd.
+    Copyright (C) 2017-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -183,6 +183,7 @@ void Foam::fixedNormalSlipFvPatchField<Type>::write(Ostream& os) const
 {
     transformFvPatchField<Type>::write(os);
     fixedValue_.writeEntry("fixedValue", os);
+    this->writeEntry("value", os);
 }
 
 

src/finiteVolume/fields/fvPatchFields/derived/fixedNormalSlip/fixedNormalSlipFvPatchField.H

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -30,28 +31,44 @@ Group
     grpGenericBoundaryConditions grpWallBoundaryConditions
 
 Description
-    This boundary condition sets the patch-normal component to a fixed value.
+    This boundary condition sets the patch-normal component to the field (vector
+    or tensor) to the patch-normal component of a user specified field.
+    The tangential component is treated as slip, i.e. copied from the internal
+    field.
 
 Usage
-    \table
-        Property     | Description             | Required    | Default value
-        fixedValue   | fixed value             | yes         |
-    \endtable
-
     Example of the boundary condition specification:
     \verbatim
     <patchName>
     {
+        // Mandatory entries (unmodifiable)
         type            fixedNormalSlip;
-        fixedValue      uniform 0;     // example entry for a scalar field
+        fixedValue      uniform (1 0 0);    // example entry for a vector field
+
+        // Mandatory/Optional (inherited) entries
+        ...
     }
     \endverbatim
 
+    where the entries mean:
+    \table
+      Property     | Description                      | Type    | Reqd | Deflt
+      type         | Type name: fixedNormalSlip       | word    | yes  | -
+      fixedValue   | User-defined value the normal component of which  <!--
+                   --> the boundary is set to                          <!--
+                   -->                | vectorField/tensorField | yes  | -
+    \endtable
+
+    The inherited entries are elaborated in:
+      - \link transformFvPatchField.H \endlink
+      - \link fvPatchField.H \endlink
+
 See also
     Foam::transformFvPatchField
 
 SourceFiles
     fixedNormalSlipFvPatchField.C
+    fixedNormalSlipFvPatchFields.C
 
 \*---------------------------------------------------------------------------*/
 
@@ -74,7 +91,7 @@ class fixedNormalSlipFvPatchField
 :
     public transformFvPatchField<Type>
 {
-    // Private data
+    // Private Data
 
         //- Value the normal component of which the boundary is set to
         Field<Type> fixedValue_;
@@ -104,7 +121,7 @@ public:
         );
 
         //- Construct by mapping given fixedNormalSlipFvPatchField
-        //  onto a new patch
+        //- onto a new patch
         fixedNormalSlipFvPatchField
         (
             const fixedNormalSlipFvPatchField<Type>&,
@@ -148,7 +165,7 @@ public:
         }
 
 
-    // Member functions
+    // Member Functions
 
         // Access
 
@@ -158,37 +175,36 @@ public:
                 return false;
             }
 
+            //- Return user-defined input field
+            virtual Field<Type>& fixedValue()
+            {
+                return fixedValue_;
+            }
+
+            //- Return user-defined input field as const field
+            virtual const Field<Type>& fixedValue() const
+            {
+                return fixedValue_;
+            }
+
 
-        // Mapping functions
+        // Mapping
 
             //- Map (and resize as needed) from self given a mapping object
             virtual void autoMap
             (
-                const fvPatchFieldMapper&
+                const fvPatchFieldMapper& m
             );
 
             //- Reverse map the given fvPatchField onto this fvPatchField
             virtual void rmap
             (
-                const fvPatchField<Type>&,
-                const labelList&
+                const fvPatchField<Type>& ptf,
+                const labelList& addr
             );
 
 
-        // Return defining fields
-
-            virtual Field<Type>& fixedValue()
-            {
-                return fixedValue_;
-            }
-
-            virtual const Field<Type>& fixedValue() const
-            {
-                return fixedValue_;
-            }
-
-
-        // Evaluation functions
+        // Evaluation
 
             //- Return gradient at boundary
             virtual tmp<Field<Type>> snGrad() const;
@@ -208,7 +224,7 @@ public:
         virtual void write(Ostream&) const;
 
 
-    // Member operators
+    // Member Operators
 
         virtual void operator=(const UList<Type>&) {}
 

[Johan Roenby]

A correction to my submitted issue: I wrote that the value in the write funtion is needed "for restart and visualisation in paraview". In fact, restart will probably work correctly without the value written out because evaluate() is called by the dict-reading constructor and, indeed, this reconstructs the face values on the patch correctly using the fixedValue and slip condition.

The point about paraview not showing the correct velocity on a patch when using the BC still holds. I have confirmed that, and that the addition of the value in write solves this (I used paraview, not paraFoam). So one could argue that this is a paraview OpenFOAM reader problem, rather than a problem with the BC implementation itself.