This reverts commit 3cfc54ba.

See also commit 22f4ad32

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1938

Because C++ does not support overloading based on the return-type there
is a problem defining both const and non-const member functions which
are resolved based on the const-ness of the object for which they are
called rather than the intent of the programmer declared via the
const-ness of the returned type.  The issue for the "boundaryField()"
member function is that the non-const version increments the
event-counter and checks the state of the stored old-time fields in case
the returned value is altered whereas the const version has no
side-effects and simply returns the reference.  If the the non-const
function is called within the patch-loop the event-counter may overflow.
To resolve this it in necessary to avoid calling the non-const form of
"boundaryField()" if the results is not altered and cache the reference
outside the patch-loop when mutation of the patch fields is needed.

The most straight forward way of resolving this problem is to name the
const and non-const forms of the member functions differently e.g. the
non-const form could be named:

    mutableBoundaryField()
    mutBoundaryField()
    nonConstBoundaryField()
    boundaryFieldRef()

Given that in C++ a reference is non-const unless specified as const:
"T&" vs "const T&" the logical convention would be

    boundaryFieldRef()
    boundaryFieldConstRef()

and given that the const form which is more commonly used is it could
simply be named "boundaryField()" then the logical convention is

    GeometricBoundaryField& boundaryFieldRef();

    inline const GeometricBoundaryField& boundaryField() const;

This is also consistent with the new "tmp" class for which non-const
access to the stored object is obtained using the ".ref()" member function.

This new convention for non-const access to the components of
GeometricField will be applied to "dimensionedInternalField()" and "internalField()" in the
future, i.e. "dimensionedInternalFieldRef()" and "internalFieldRef()".

Also added the new prghTotalHydrostaticPressure p_rgh BC which uses the
hydrostatic pressure field as the reference state for the far-field
which provides much more accurate entrainment is large open domains
typical of many fire simulations.

The hydrostatic field solution is controlled by the optional entries in
the fvSolution.PIMPLE dictionary, e.g.

    hydrostaticInitialization yes;
    nHydrostaticCorrectors 5;

and the solver must also be specified for the hydrostatic p_rgh field
ph_rgh e.g.

    ph_rgh
    {
        $p_rgh;
    }

Suitable boundary conditions for ph_rgh cannot always be derived from
those for p_rgh and so the ph_rgh is read to provide them.

To avoid accuracy issues with IO, restart and post-processing the p_rgh
and ph_rgh the option to specify a suitable reference pressure is
provided via the optional pRef file in the constant directory, e.g.

    dimensions      [1 -1 -2 0 0 0 0];
    value           101325;

which is used in the relationship between p_rgh and p:

    p = p_rgh + rho*gh + pRef;

Note that if pRef is specified all pressure BC specifications in the
p_rgh and ph_rgh files are relative to the reference to avoid round-off
errors.

For examples of suitable BCs for p_rgh and ph_rgh for a range of
fireFoam cases please study the tutorials in
tutorials/combustion/fireFoam/les which have all been updated.

Henry G. Weller
CFD Direct Ltd.

Patch contributed by Juho Peltola, VTT

The new JohnsonJacksonSchaefferFrictionalStress model is included and
the LBend tutorial case to demonstrate the need for the changes to the
frictional stress models.

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=2058

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=2059

Using method based on
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070017872.pdf
but simplified for the case where the quaternions are similar.

inline Foam::vector Foam::septernion::transformPoint(const vector& v) const
{
    return r().transform(v - t());
}

Now there is a 1:1 correspondence between septernion and
spatialTransform and a septernion constructor from spatialTransform
provided.

Additionally "septernion::transform" has been renamed
"septernion::transformPoint" to clarify that it transforms coordinate
points rather than displacements or other relative vectors.

Replaced with 'unitQuaterion()' virtual function to indicate if the
joint uses a unit quaternion to represent rotation.

rigidBodyDynamics: Simplify handling of quaternions by maintaining a unit quaternion in the joint state field 'q'

'w' is now obtained from 'v' using the relation w = sqrt(1 - |sqr(v)|)
and 'v' is stored in the joint state field 'q' and integrated in the
usual manner but corrected using quaternion transformations.

rigidBodyDynamics/rigidBodySolvers: Added run-time selectable solvers to integrate the rigid-body motion

Currently supported solvers: symplectic, Newmark, CrankNicolson

The symplectic solver should only be used if iteration over the forces
and body-motion is not required.  Newmark and CrankNicolson both require
iteration to provide 2nd-order behavior.

See applications/test/rigidBodyDynamics/spring for an example of the
application of the Newmark solver.

This development is sponsored by Carnegie Wave Energy Ltd.

This is a more convenient way of maintaining the state or multiple
states (for higher-order integration), storing, retrieving and passing
between processors.

applications/test/rigidBodyDynamics/spring: Test of the linear spring with damper restraint
Damped simple harmonic motion of a weight on a spring is simulated and
the results compared with analytical solution

    Test-spring
    gnuplot spring.gnuplot
    evince spring.eps

This development is sponsored by Carnegie Wave Energy Ltd.

rigidBodyDynamics/bodies: Complete set of clone functions to support copy construction and assignment

e.g. (fvc::interpolate(HbyA) & mesh.Sf()) -> fvc::flux(HbyA)

This removes the need to create an intermediate face-vector field when
computing fluxes which is more efficient, reduces the peak storage and
improved cache coherency in addition to providing a simpler and cleaner
API.

applications/test/rigidBodyDynamics/pendulum: Simplified using sphere constructor and body lookup by name