src/finiteVolume/cfdTools: Removed unused code

Solver modules have replaced code that was previously shared between
solvers by means of #include-ing header files. Some of these headers are
now unused and have been removed. Others are only now used in a single
solver and have been moved into that solver.

applications/solvers/multiphase/cavitatingFoam/createUfIfPresent.H

@@ -0,0 +1,54 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2017-2023 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Global
+    createUfIfPresent
+
+Description
+    Creates and initialises the velocity field Uf if required.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+autoPtr<surfaceVectorField> Uf;
+
+if (mesh.dynamic())
+{
+    Info<< "Constructing face velocity Uf\n" << endl;
+
+    Uf = new surfaceVectorField
+    (
+        IOobject
+        (
+            "Uf",
+            runTime.name(),
+            mesh,
+            IOobject::READ_IF_PRESENT,
+            IOobject::AUTO_WRITE
+        ),
+        fvc::interpolate(U)
+    );
+}
+
+// ************************************************************************* //

applications/solvers/multiphase/driftFluxFoam/gh.H

@@ -0,0 +1,4 @@
+    Info<< "Calculating field g.h\n" << endl;
+    dimensionedScalar ghRef(- mag(g)*hRef);
+    volScalarField gh("gh", (g & mesh.C()) - ghRef);
+    surfaceScalarField ghf("ghf", (g & mesh.Cf()) - ghRef);

applications/solvers/multiphase/driftFluxFoam/readhRef.H

@@ -0,0 +1,13 @@
+    Info<< "\nReading hRef" << endl;
+    uniformDimensionedScalarField hRef
+    (
+        IOobject
+        (
+            "hRef",
+            runTime.constant(),
+            mesh,
+            IOobject::READ_IF_PRESENT,
+            IOobject::NO_WRITE
+        ),
+        dimensionedScalar(dimLength, 0)
+    );