ENH: New vibro-acoustic model suite

- New solver: `acousticFoam`
  - New base finite-area region class: `regionFaModel`
  - New base shell model classes:
    - `vibrationShellModel`
    - `thermalShellModel`
  - New shell models:
    - A vibration-shell model: `KirchhoffShell`
    - A thermal-shell model: `thermalShell`
  - New finite-area/finite-volume boundary conditions:
    - `clampedPlate`
    - `timeVaryingFixedValue`
    - `acousticWaveTransmissive`
  - New base classes for `fvOption` of finite-area methods: `faOption`
  - New `faOption`s:
    - `contactHeatFluxSource`
    - `externalFileSource`
    - `externalHeatFluxSource`
    - `jouleHeatingSource`
  - New tutorial: `compressible/acousticFoam/obliqueAirJet`

Signed-off-by: Kutalmis Bercin <kutalmis.bercin@esi-group.com>

src/faOptions/sources/derived/externalFileSource/externalFileSource.H

@@ -0,0 +1,169 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019-2020 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+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::fa::externalFileSource
+
+Group
+    grpFaOptionsSources
+
+Description
+    Applies sources on a specified field within a specified region
+    by using an external table file for compressible flows.
+
+Usage
+    Minimal example by using \c constant/faOptions:
+    \verbatim
+    externalFileSource1
+    {
+        // Mandatory entries (unmodifiable)
+        type                externalFileSource;
+        fieldName           <fieldName>;
+        tableName           <tableFileName.dat>;
+
+        // Mandatory/Optional (inherited) entries
+        ...
+    }
+    \endverbatim
+
+    where the entries mean:
+    \table
+      Property  | Description                    | Type  | Reqd | Dflt
+      type      | Type name: externalFileSource  | word  | yes  | -
+      fieldName | Name of operand field          | word  | yes  | -
+      tableName | Name of operand table file     | word  | yes  | -
+    \endtable
+
+    The inherited entries are elaborated in:
+     - \link faOption.H \endlink
+     - \link faceSetOption.H \endlink
+
+See also
+  - Foam::PatchFunction1Types
+
+SourceFiles
+    externalFileSource.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef fa_externalFileSource_H
+#define fa_externalFileSource_H
+
+#include "faOption.H"
+#include "areaFields.H"
+#include "faceSetOption.H"
+#include "MappedFile.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fa
+{
+
+/*---------------------------------------------------------------------------*\
+                        Class externalFileSource Declaration
+\*---------------------------------------------------------------------------*/
+
+class externalFileSource
+:
+    public faceSetOption
+{
+    // Private Data
+
+        //- Name of the field to apply this source
+        word fieldName_;
+
+        //- Name of the table
+        word tableName_;
+
+        //- External pressure field
+        areaScalarField pExt_;
+
+        //- Mapped data from file
+        autoPtr<PatchFunction1Types::MappedFile<scalar>> value_;
+
+        //- Current time index (used for updating)
+        label curTimeIndex_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("externalFileSource");
+
+
+    // Constructors
+
+        //- Construct from explicit source name and mesh
+        externalFileSource
+        (
+            const word& sourceName,
+            const word& modelType,
+            const dictionary& dict,
+            const fvPatch& patch
+        );
+
+        //- No copy construct
+        externalFileSource(const externalFileSource&) = delete;
+
+        //- No copy assignment
+        void operator=(const externalFileSource&) = delete;
+
+
+    //- Destructor
+    virtual ~externalFileSource() = default;
+
+
+    // Member Functions
+
+        // Evaluation
+
+            //- Add explicit contribution to compressible momentum equation
+            virtual void addSup
+            (
+                const areaScalarField& rho,
+                faMatrix<scalar>& eqn,
+                const label fieldi
+            );
+
+
+        // IO
+
+            //- Read source dictionary
+            virtual bool read(const dictionary& dict);
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace fa
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //