ENH: electricPotential: add finite-volume constraint hook

src/functionObjects/solvers/electricPotential/electricPotential.C

@@ -217,6 +217,7 @@ Foam::functionObjects::electricPotential::electricPotential
             IOobject::scopedName(typeName, "E")
         )
     ),
+    fvOptions_(mesh_),
     nCorr_(1),
     writeDerivedFields_(false),
     electricField_(false)
@@ -341,6 +342,11 @@ bool Foam::functionObjects::electricPotential::read(const dictionary& dict)
         }
     }
 
+    if (const dictionary* dictptr = dict.findDict("fvOptions"))
+    {
+        fvOptions_.reset(*dictptr);
+    }
+
     return true;
 }
 
@@ -363,6 +369,8 @@ bool Foam::functionObjects::electricPotential::execute()
 
         eVEqn.relax();
 
+        fvOptions_.constrain(eVEqn);
+
         eVEqn.solve();
     }
 

src/functionObjects/solvers/electricPotential/electricPotential.H

@@ -123,6 +123,7 @@ Usage
         V                     <word>;
         electricField         <bool>;
         E                     <word>;
+        fvOptions             <dict>;
 
         // Inherited entries
         ...
@@ -141,10 +142,12 @@ Usage
       V    | Name of electric potential field | word | no | electricPotential:V
       electricField | Flag to calculate electric field  | bool | no | false
       E    | Name of electric field           | word | no | electricPotential:E
+      fvOptions | List of finite-volume options       | dict | no   | -
     \endtable
 
     The inherited entries are elaborated in:
       - \link functionObject.H \endlink
+      - \link fvOption.H \endlink
 
     Fields written out when the \c writeDerivedFields entry is \c true:
     \table
@@ -153,6 +156,9 @@ Usage
       Charge density  | volScalarField   | \<time\>/electricPotential:rho
     \endtable
 
+Note
+  - Only constraint-type finite-volume options can be used.
+
 SourceFiles
     electricPotential.C
 
@@ -163,6 +169,7 @@ SourceFiles
 
 #include "fvMeshFunctionObject.H"
 #include "volFields.H"
+#include "fvOptionList.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -208,6 +215,9 @@ class electricPotential
         //- Name of electric field
         word Ename_;
 
+        //- Run-time selectable finite volume options
+        fv::optionList fvOptions_;
+
         //- Number of corrector iterations
         int nCorr_;