interpolatingSolidBodyMotionSolver: New solid-body mesh-motion solver which intepolates the motion

Description
    Solid-body motion of the mesh specified by a run-time selectable motion
    function.  Applies SLERP interpolation of movement as function of
    distance to the object surface to move the mesh points.

src/dynamicMesh/motionSolvers/displacement/solidBody/interpolatingSolidBodyMotionSolver/interpolatingSolidBodyMotionSolver.C

@@ -0,0 +1,159 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "interpolatingSolidBodyMotionSolver.H"
+#include "addToRunTimeSelectionTable.H"
+#include "pointPatchDist.H"
+#include "pointConstraints.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(interpolatingSolidBodyMotionSolver, 0);
+
+    addToRunTimeSelectionTable
+    (
+        motionSolver,
+        interpolatingSolidBodyMotionSolver,
+        dictionary
+    );
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::interpolatingSolidBodyMotionSolver::interpolatingSolidBodyMotionSolver
+(
+    const polyMesh& mesh,
+    const IOdictionary& dict
+)
+:
+    points0MotionSolver(mesh, dict, typeName),
+    SBMFPtr_(solidBodyMotionFunction::New(coeffDict(), mesh.time())),
+    patches_(wordReList(coeffDict().lookup("patches"))),
+    patchSet_(mesh.boundaryMesh().patchSet(patches_)),
+    CofG_(coeffDict().lookup("CofG")),
+    di_(readScalar(coeffDict().lookup("innerDistance"))),
+    do_(readScalar(coeffDict().lookup("outerDistance"))),
+    scale_
+    (
+        IOobject
+        (
+            "motionScale",
+            mesh.time().timeName(),
+            mesh,
+            IOobject::NO_READ,
+            IOobject::NO_WRITE,
+            false
+        ),
+        pointMesh::New(mesh),
+        dimensionedScalar("zero", dimless, 0.0)
+    )
+{
+    // Calculate scaling factor everywhere
+
+    {
+        const pointMesh& pMesh = pointMesh::New(mesh);
+
+        pointPatchDist pDist(pMesh, patchSet_, points0());
+
+        // Scaling: 1 up to di then linear down to 0 at do away from patches
+        scale_.primitiveFieldRef() =
+            min
+            (
+                max
+                (
+                    (do_ - pDist.primitiveField())/(do_ - di_),
+                    scalar(0)
+                ),
+                scalar(1)
+            );
+
+        // Convert the scale function to a cosine
+        scale_.primitiveFieldRef() =
+            min
+            (
+                max
+                (
+                    0.5
+                  - 0.5
+                   *cos(scale_.primitiveField()
+                   *Foam::constant::mathematical::pi),
+                    scalar(0)
+                ),
+                scalar(1)
+            );
+
+        pointConstraints::New(pMesh).constrain(scale_);
+        scale_.write();
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::interpolatingSolidBodyMotionSolver::~interpolatingSolidBodyMotionSolver()
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+Foam::tmp<Foam::pointField>
+Foam::interpolatingSolidBodyMotionSolver::curPoints() const
+{
+    const pointField& points0 = this->points0();
+    const septernion s = SBMFPtr_().transformation();
+
+    tmp<pointField> tpoints(new pointField(points0));
+    pointField& points = tpoints.ref();
+
+    forAll(points, pointi)
+    {
+        // Move non-stationary points
+        if (scale_[pointi] > small)
+        {
+            // Use solid-body motion where scale = 1
+            if (scale_[pointi] > 1 - small)
+            {
+                points[pointi] =
+                    CofG_ + s.transformPoint(points0[pointi] - CofG_);
+            }
+            // Slerp septernion interpolation
+            else
+            {
+                const septernion ss(slerp(septernion::I, s, scale_[pointi]));
+
+                points[pointi] =
+                    CofG_ + ss.transformPoint(points0[pointi] - CofG_);
+            }
+        }
+    }
+
+    return tpoints;
+}
+
+
+// ************************************************************************* //

src/dynamicMesh/motionSolvers/displacement/solidBody/interpolatingSolidBodyMotionSolver/interpolatingSolidBodyMotionSolver.H

@@ -0,0 +1,130 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2018 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/>.
+
+Class
+    Foam::interpolatingSolidBodyMotionSolver
+
+Description
+    Solid-body motion of the mesh specified by a run-time selectable motion
+    function.  Applies SLERP interpolation of movement as function of
+    distance to the object surface to move the mesh points.
+
+SourceFiles
+    interpolatingSolidBodyMotionSolver.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef interpolatingSolidBodyMotionSolver_H
+#define interpolatingSolidBodyMotionSolver_H
+
+#include "points0MotionSolver.H"
+#include "solidBodyMotionFunction.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+        Class interpolatingSolidBodyMotionSolver Declaration
+\*---------------------------------------------------------------------------*/
+
+class interpolatingSolidBodyMotionSolver
+:
+    public points0MotionSolver
+{
+    // Private data
+
+        //- The motion control function
+        autoPtr<solidBodyMotionFunction> SBMFPtr_;
+
+        wordReList patches_;
+
+        //- Patches to integrate forces
+        const labelHashSet patchSet_;
+
+        //- Center of gravity read from dictionary
+        vector CofG_;
+
+        //- Inner morphing distance (limit of solid-body region)
+        const scalar di_;
+
+        //- Outer morphing distance (limit of linear interpolation region)
+        const scalar do_;
+
+        //- Current interpolation scale (1 at patches, 0 at distance_)
+        pointScalarField scale_;
+
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        interpolatingSolidBodyMotionSolver
+        (
+            const interpolatingSolidBodyMotionSolver&
+        );
+
+        //- Disallow default bitwise assignment
+        void operator=(const interpolatingSolidBodyMotionSolver&);
+
+
+public:
+
+    //- Runtime type information
+    TypeName("interpolatingSolidBody");
+
+
+    // Constructors
+
+        //- Construct from polyMesh and IOdictionary
+        interpolatingSolidBodyMotionSolver
+        (
+            const polyMesh&,
+            const IOdictionary& dict
+        );
+
+
+    //- Destructor
+    ~interpolatingSolidBodyMotionSolver();
+
+
+    // Member Functions
+
+        //- Return point location obtained from the current motion field
+        virtual tmp<pointField> curPoints() const;
+
+        //- Solve for motion
+        virtual void solve()
+        {}
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //