The standard naming convention for heat flux is "q" and this is used for the
conductive and convective heat fluxes is OpenFOAM.  The use of "Qr" for
radiative heat flux is an anomaly which causes confusion, particularly for
boundary conditions in which "Q" is used to denote power in Watts.  The name of
the radiative heat flux has now been corrected to "qr" and all models, boundary
conditions and tutorials updated.

by combining with and rationalizing functionality from
turbulentHeatFluxTemperatureFvPatchScalarField.
externalWallHeatFluxTemperatureFvPatchScalarField now replaces
turbulentHeatFluxTemperatureFvPatchScalarField which is no longer needed and has
been removed.

Description
    This boundary condition applies a heat flux condition to temperature
    on an external wall in one of three modes:

      - fixed power: supply Q
      - fixed heat flux: supply q
      - fixed heat transfer coefficient: supply h and Ta

    where:
    \vartable
        Q  | Power [W]
        q  | Heat flux [W/m^2]
        h  | Heat transfer coefficient [W/m^2/K]
        Ta | Ambient temperature [K]
    \endvartable

    For heat transfer coefficient mode optional thin thermal layer resistances
    can be specified through thicknessLayers and kappaLayers entries.

    The thermal conductivity \c kappa can either be retrieved from various
    possible sources, as detailed in the class temperatureCoupledBase.

Usage
    \table
    Property     | Description                 | Required | Default value
    mode         | 'power', 'flux' or 'coefficient' | yes |
    Q            | Power [W]                   | for mode 'power'     |
    q            | Heat flux [W/m^2]           | for mode 'flux'     |
    h            | Heat transfer coefficient [W/m^2/K] | for mode 'coefficent' |
    Ta           | Ambient temperature [K]     | for mode 'coefficient' |
    thicknessLayers | Layer thicknesses [m] | no |
    kappaLayers  | Layer thermal conductivities [W/m/K] | no |
    qr           | Name of the radiative field | no | none
    qrRelaxation | Relaxation factor for radiative field | no | 1
    kappaMethod  | Inherited from temperatureCoupledBase | inherited |
    kappa        | Inherited from temperatureCoupledBase | inherited |
    \endtable

    Example of the boundary condition specification:
    \verbatim
    <patchName>
    {
        type            externalWallHeatFluxTemperature;

        mode            coefficient;

        Ta              uniform 300.0;
        h               uniform 10.0;
        thicknessLayers (0.1 0.2 0.3 0.4);
        kappaLayers     (1 2 3 4);

        kappaMethod     fluidThermo;

        value           $internalField;
    }
    \endverbatim

Description
    Temperature-dependent surface tension model in which the surface tension
    function provided by the phase Foam::liquidProperties class is used.

Usage
    \table
        Property     | Description               | Required    | Default value
        phase        | Phase name                | yes         |
    \endtable

    Example of the surface tension specification:
    \verbatim
        sigma
        {
            type    liquidProperties;
            phase   water;
        }
    \endverbatim

for use with e.g. compressibleInterFoam, see
tutorials/multiphase/compressibleInterFoam/laminar/depthCharge2D

snappyHexMesh produces a far better quality AMI interface using a cylindrical background mesh,
leading to much more robust performance, even on a relatively coarse mesh.  The min/max AMI
weights remain close to 1 as the mesh moves, giving better conservation.

The rotating geometry template cases are configured with a blockMeshDict file for a cylindrical
background mesh aligned along the z-axis.  The details of use are found in the README and
blockMeshDict files.

Uncommenting the patches provides a convenient way to use the patches in the background mesh
to define the external boundary of the final mesh.  Replaces previous setup with a separate
blockMeshDict.extPatches file.

Combining a Function1 temperature dependency with a distributionModel stochastic
perturbation.

Resolves bug-report https://bugs.openfoam.org/view.php?id=2513

tutorials/multiphase: Removed unnecessary specification of name and dimensions for transport properties

These models have been particularly designed for use in the VoF solvers, both
incompressible and compressible.  Currently constant and temperature dependent
surface tension models are provided but it easy to write models in which the
surface tension is evaluated from any fields held by the mesh database.

Resolves bug-report https://bugs.openfoam.org/view.php?id=2514

This update does not change the operation or controls of the regionModels, it is
to aid understanding of the code.

Created a base-class from contactAngleForce from which the
distributionContactAngleForce (for backward compatibility) and the new
temperatureDependentContactAngleForce are derived:

Description
    Temperature dependent contact angle force

    The contact angle in degrees is specified as a \c Function1 type, to
    enable the use of, e.g.  contant, polynomial, table values.

See also
    Foam::regionModels::surfaceFilmModels::contactAngleForce
    Foam::Function1Types

SourceFiles
    temperatureDependentContactAngleForce.C

according to

        Bai et al, `Modelling of gasoline spray impingement', Atom. Sprays,
        vol 12, pp 1-27, 2002

Resolves bug-report https://bugs.openfoam.org/view.php?id=2478

Demonstrates meshing a cylinder with hemispehrical ends using snappyHexMesh with
a polar background mesh that uses the point and edge projection feature of blockMesh.
The case prescribes a multiMotion on the cylinder, combining an oscillatingLinearMotion
and transverse rotatingMotion.

    Off-centering is specified via the mandatory coefficient \c ocCoeff in the
    range [0,1] following the scheme name e.g.
    \verbatim
    ddtSchemes
    {
        default         CrankNicolson 0.9;
    }
    \endverbatim
    or with an optional "ramp" function to transition from the Euler scheme to
    Crank-Nicolson over a initial period to avoid start-up problems, e.g.
    \verbatim
    ddtSchemes
    {
        default         CrankNicolson
        ocCoeff
        {
            type scale;
            scale linearRamp;
            duration 0.01;
            value 0.9;
        };
    }
    \endverbatim

Note this functionality is experimental and the specification and implementation
may change if issues arise.

Patch contributed by Timo Niemi, VTT.
Resolves bug-report https://bugs.openfoam.org/view.php?id=2510

Resolves bug-report https://bugs.openfoam.org/view.php?id=2512

Applied to eigen-value calculations. Fixed repeated-eigen-value issues
in eigen-vector generation.

Resolves bug-report https://bugs.openfoam.org/view.php?id=2511

Resolves bug-report https://bugs.openfoam.org/view.php?id=2507