phaseScalarTransport: Improved interface and documentation

This function now looks up an alphaPhi field by default and exits with
an error if the field cannot be found. In order to solve for alphaPhi a
new 'solveAlphaPhi' switch has to be set.

The documentation has been updated to reflect the fact that the VoF
solvers now store all the alphaPhi fluxes necessary for a in-phase
equation to be constructed.

The phaseScalarTransport function has been added to the damBreakLaminar
tutorial.

src/functionObjects/solvers/phaseScalarTransport/phaseScalarTransport.C

@@ -90,7 +90,7 @@ Foam::volScalarField& Foam::functionObjects::phaseScalarTransport::Phi()
             (
                 IOobject
                 (
-                    "Phi" + s_.name(),
+                    typedName(IOobject::groupName("Phi", phaseName_)),
                     time_.name(),
                     mesh_,
                     IOobject::READ_IF_PRESENT,
@@ -112,16 +112,11 @@ Foam::volScalarField& Foam::functionObjects::phaseScalarTransport::Phi()
 Foam::tmp<Foam::surfaceScalarField>
 Foam::functionObjects::phaseScalarTransport::alphaPhi()
 {
-    // If alphaPhi exists then return it
+    if (!solveAlphaPhi_)
-    if (mesh_.foundObject<surfaceScalarField>(alphaPhiName_))
     {
         return mesh_.lookupObject<surfaceScalarField>(alphaPhiName_);
     }
 
-    // Otherwise generate it ...
-    Info<< type() << ": " << surfaceScalarField::typeName << " "
-        << alphaPhiName_ << " was not found, so generating it" << endl;
-
     const volScalarField& alpha =
         mesh_.lookupObject<volScalarField>(alphaName_);
     const surfaceScalarField& phi =
@@ -288,8 +283,6 @@ Foam::functionObjects::phaseScalarTransport::phaseScalarTransport
     fvMeshFunctionObject(name, runTime, dict),
     fieldName_(dict.lookup("field")),
     phaseName_(IOobject::group(fieldName_)),
-    nCorr_(0),
-    residualAlpha_(rootSmall),
     s_
     (
         IOobject
@@ -330,18 +323,20 @@ bool Foam::functionObjects::phaseScalarTransport::read(const dictionary& dict)
 {
     fvMeshFunctionObject::read(dict);
 
+    solveAlphaPhi_ = dict.lookupOrDefault<bool>("solveAlphaPhi", false);
+
     alphaName_ =
         dict.lookupOrDefault<word>
         (
             "alpha",
             IOobject::groupName("alpha", phaseName_)
         );
+    const word defaultAlphaPhiName =
+        IOobject::groupName("alphaPhi", phaseName_);
     alphaPhiName_ =
-        dict.lookupOrDefault<word>
+        solveAlphaPhi_
-        (
+      ? typedName(defaultAlphaPhiName)
-            "alphaPhi",
+      : dict.lookupOrDefault<word>("alphaPhi", defaultAlphaPhiName);
-            IOobject::groupName("alphaPhi", phaseName_)
-        );
     phiName_ = dict.lookupOrDefault<word>("phi", "phi");
     rhoName_ =
         dict.lookupOrDefault<word>
@@ -356,8 +351,8 @@ bool Foam::functionObjects::phaseScalarTransport::read(const dictionary& dict)
     alphaD_ = dict.lookupOrDefault<scalar>("alphaD", 1);
     alphaDt_ = dict.lookupOrDefault<scalar>("alphaDt", 1);
 
-    dict.readIfPresent("nCorr", nCorr_);
+    nCorr_ = dict.lookupOrDefault<label>("nCorr", 0);
-    dict.readIfPresent("residualAlpha", residualAlpha_);
+    residualAlpha_ = dict.lookupOrDefault<scalar>("residualAlpha", rootSmall);
     writeAlphaField_ = dict.lookupOrDefault<bool>("writeAlphaField", true);
 
     return true;

src/functionObjects/solvers/phaseScalarTransport/phaseScalarTransport.H

@@ -37,27 +37,25 @@ Description
     detailed below. Note that the phase-name will be determined by stripping
     the extension from the supplied field name.
 
-    If \c alphaPhi is specified and found in the database then it will be used
+    If the solver does not provide an \c alphaPhi flux, or that flux is for
-    to transport the field. This is the likely mode of operation if this
+    some reason unreliable, then the \c solveAlphaPhi switch can be used to
-    function is used with Euler-Euler solvers, in which \c alphaPhi -like
+    make this function solve a pressure-like equation from which \c alphaPhi is
-    fluxes are available. If \c alphaPhi is not found, then a pressure-like
+    recovered.
-    equation will be solved in order to construct it so that it exactly matches
-    the time-derivative of the phase volume or mass. This is likely to be
-    necessary in volume-of-fluid solvers where \c alphaPhi is not part of the
-    solution procedure. The pressure field name will be required in this case.
 
 Usage
     \table
-        Property        | Description                        | Req'd? | Default
+        Property        | Description                       | Req'd? | Default
-        alpha           | Name of the volume-fraction field  | no\\
+        alpha           | Name of the volume-fraction field | no\\
                         | alpha.<phase-name>
-        alphaPhi        | Name of the phase-flux field       | no\\
+        alphaPhi        | Name of the phase-flux field      | no\\
                         | alphaPhi.<phase-name>
-        p               | Name of the pressure field         | no     | p
+        solveAlphaPhi   | Solve for the alphaPhi flux, rather than looking it\\
+                          up                                | no     | false
+        p               | Name of the pressure field        | no     | p
         residualAlpha   | Small volume fraction used to stabilise the solution\\
-                        | no | rootSmall
+                                                            | no     | rootSmall
         writeAlphaField | Also write out alpha multiplied by the field\\
-                        | no | true
+                                                            |        no | true
     \endtable
 
     Example specification for incompressibleVoF:
@@ -68,7 +66,6 @@ Usage
         libs            ("libsolverFunctionObjects.so");
 
         field           s.water;
-        p               p_rgh;
     }
     \endverbatim
 
@@ -123,6 +120,9 @@ class phaseScalarTransport
         //- Name of the phase in which to solve
         const word phaseName_;
 
+        //- Solve for the alphaPhi flux, rather than looking it up (optional)
+        bool solveAlphaPhi_;
+
         //- Name of phase volume-fraction field (optional)
         word alphaName_;
 

tutorials/incompressibleVoF/damBreakLaminar/0/tracer.air.orig

@@ -0,0 +1,39 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       volScalarField;
+    location    "0";
+    object      tracer.air;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions      [];
+
+internalField   uniform 0;
+
+boundaryField
+{
+    #includeEtc "caseDicts/setConstraintTypes"
+
+    wall
+    {
+        type            zeroGradient;
+    }
+
+    atmosphere
+    {
+        type            inletOutlet;
+        inletValue      $internalField;
+        value           $internalField;
+    }
+}
+
+
+// ************************************************************************* //

tutorials/incompressibleVoF/damBreakLaminar/0/tracer.water.orig

@@ -0,0 +1,39 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       volScalarField;
+    location    "0";
+    object      tracer.water;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+dimensions      [];
+
+internalField   uniform 0;
+
+boundaryField
+{
+    #includeEtc "caseDicts/setConstraintTypes"
+
+    wall
+    {
+        type            zeroGradient;
+    }
+
+    atmosphere
+    {
+        type            inletOutlet;
+        inletValue      $internalField;
+        value           $internalField;
+    }
+}
+
+
+// ************************************************************************* //

tutorials/incompressibleVoF/damBreakLaminar/Allclean

@@ -6,10 +6,12 @@ cd ${0%/*} || exit 1    # Run from this directory
 
 cleanVoFCase
 
-rm -rf 0 system
+find 0 -type f -not -name tracer.* -delete
 
 find constant -type f -not \( \
     -name fvModels -or -name momentumTransport \
     \) -delete
 
+rm -f system/blockMeshDict
+
 #------------------------------------------------------------------------------

tutorials/incompressibleVoF/damBreakLaminar/Allrun

@@ -9,10 +9,6 @@ isTest "$@" && path=.. || path=$FOAM_TUTORIALS/incompressibleVoF
 cp -rn $path/damBreak/0 $path/damBreak/constant $path/damBreak/system .
 rm -f 0/alpha.water
 
-# Increase the number of limiter iterations
-runApplication foamDictionary system/fvSolution \
-    -entry solvers/"alpha.water.*"/nLimiterIter -set 5
-
 # Run
 runApplication blockMesh
 runApplication setFields

tutorials/incompressibleVoF/damBreakLaminar/constant/momentumTransport

@@ -16,12 +16,5 @@ FoamFile
 
 simulationType  laminar;
 
-RAS
-{
-    model           kEpsilon;
-    turbulence      on;
-    printCoeffs     on;
-}
-
 
 // ************************************************************************* //

tutorials/incompressibleVoF/damBreakLaminar/system/controlDict

@@ -0,0 +1,62 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       dictionary;
+    location    "system";
+    object      controlDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+application     foamRun;
+
+solver          incompressibleVoF;
+
+startFrom       startTime;
+
+startTime       0;
+
+stopAt          endTime;
+
+endTime         1;
+
+deltaT          0.001;
+
+writeControl    adjustableRunTime;
+
+writeInterval   0.05;
+
+purgeWrite      0;
+
+writeFormat     ascii;
+
+writePrecision  6;
+
+writeCompression off;
+
+timeFormat      general;
+
+timePrecision   6;
+
+runTimeModifiable yes;
+
+adjustTimeStep  yes;
+
+maxCo           1;
+maxAlphaCo      1;
+
+maxDeltaT       1;
+
+functions
+{
+    #includeFunc phaseScalarTransport(field=tracer.water)
+    #includeFunc phaseScalarTransport(field=tracer.air, residualAlpha=1e-6)
+}
+
+// ************************************************************************* //

tutorials/incompressibleVoF/damBreakLaminar/system/fvSchemes

@@ -0,0 +1,58 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       dictionary;
+    location    "system";
+    object      fvSchemes;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+ddtSchemes
+{
+    default         Euler;
+}
+
+gradSchemes
+{
+    default         Gauss linear;
+}
+
+divSchemes
+{
+    div(phi,alpha)  Gauss interfaceCompression vanLeer 1;
+
+    div(rhoPhi,U)   Gauss linearUpwind grad(U);
+
+    div(phi,k)      Gauss upwind;
+    div(phi,epsilon) Gauss upwind;
+    div(phi,omega)  Gauss upwind;
+
+    div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;
+
+    div(alphaPhi,tracer) Gauss vanLeer;
+}
+
+laplacianSchemes
+{
+    default         Gauss linear uncorrected;
+}
+
+interpolationSchemes
+{
+    default         linear;
+}
+
+snGradSchemes
+{
+    default         uncorrected;
+}
+
+
+// ************************************************************************* //

tutorials/incompressibleVoF/damBreakLaminar/system/fvSolution

@@ -0,0 +1,90 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       dictionary;
+    location    "system";
+    object      fvSolution;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+solvers
+{
+    "alpha.water.*"
+    {
+        nAlphaCorr      2;
+        nAlphaSubCycles 1;
+
+        MULESCorr       yes;
+        nLimiterIter    5;
+
+        solver          smoothSolver;
+        smoother        symGaussSeidel;
+        tolerance       1e-8;
+        relTol          0;
+    }
+
+    "pcorr.*"
+    {
+        solver          PCG;
+        preconditioner  DIC;
+        tolerance       1e-5;
+        relTol          0;
+    }
+
+    p_rgh
+    {
+        solver          PCG;
+        preconditioner  DIC;
+        tolerance       1e-07;
+        relTol          0.05;
+    }
+
+    p_rghFinal
+    {
+        $p_rgh;
+        relTol          0;
+    }
+
+    "(U|k|epsilon|omega).*"
+    {
+        solver          smoothSolver;
+        smoother        symGaussSeidel;
+        tolerance       1e-06;
+        relTol          0;
+        minIter         1;
+    }
+
+    "tracer.*"
+    {
+        solver          PBiCGStab;
+        preconditioner  DILU;
+        tolerance       1e-06;
+        relTol          0;
+    }
+}
+
+PIMPLE
+{
+    momentumPredictor   no;
+    nOuterCorrectors    1;
+    nCorrectors         3;
+    nNonOrthogonalCorrectors 0;
+}
+
+relaxationFactors
+{
+    equations
+    {
+        ".*"                1;
+    }
+}
+
+
+// ************************************************************************* //

tutorials/incompressibleVoF/damBreakLaminar/system/setFieldsDict

@@ -0,0 +1,53 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Version:  dev
+     \\/     M anipulation  |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    format      ascii;
+    class       dictionary;
+    location    "system";
+    object      setFieldsDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+defaultFieldValues
+(
+    volScalarFieldValue alpha.water 0
+    volScalarFieldValue tracer.water 0
+    volScalarFieldValue tracer.air 0
+);
+
+regions
+(
+    boxToCell
+    {
+        box (0 0 -1) (0.1461 0.292 1);
+        fieldValues
+        (
+            volScalarFieldValue alpha.water 1
+        );
+    }
+    boxToCell
+    {
+        box (0 0 -1) (0.1461 0.146 1);
+        fieldValues
+        (
+            volScalarFieldValue tracer.water 1
+        );
+    }
+    boxToCell
+    {
+        box (0 0.292 -1) (0.1461 0.438 1);
+        fieldValues
+        (
+            volScalarFieldValue tracer.air 1
+        );
+    }
+);
+
+
+// ************************************************************************* //