A set of routines for cutting polyhedra have been added. These can cut
polyhedral cells based on the adjacent point values and an iso-value
which defines the surface. The method operates directly on the
polyhedral cells; it does not decompose them into tetrahedra at any
point. The routines can compute the cut topology as well as integrals of
properties above and below the cut surface.
An iso-surface algorithm has been added based on these polyhedral
cutting routines. It is significantly more robust than the previous
algorithm, and produces compact surfaces equivalent to the previous
algorithm's maximum filtering level. It is also approximately 3 times
faster than the previous algorithm, and 10 times faster when run
repeatedly on the same set of cells (this is because some addressing is
cached and reused).
This algorithm is used by the 'isoSurface', 'distanceSurface' and
'cutPlane' sampled surfaces.
The 'cutPlane' sampled surface is a renaming of 'cuttingPlane' to make
it consistent with the corresponding packaged function. The name
'cuttingPlane' has been retained for backwards compatibility and can
still be used to select a 'cutPlane' surface. The legacy 'plane' surface
has been removed.
The 'average' keyword has been removed from specification of these
sampled surfaces as cell-centred values are no longer used in the
generation of or interpolation to an iso-surface. The 'filtering'
keyword has also been removed as it relates to options within the
previous algorithm. Zone support has been reinstated into the
'isoSurface' sampled surface. Interpolation to all these sampled
surfaces has been corrected to exactly match the user-selected
interpolation scheme, and the interpolation procedure no longer
unnecessarily re-generates data that is already available.
This is an inlet-outlet condition where the inlet value differs above
and below a wave interface. It can be used as follows:
inlet
{
type waveInletOutlet;
inletValueAbove 0.01;
inletValueBelow 0.1;
}
This addition allows for theoretical wave models to be utilised for
initialisation and as boundary conditions. Multiple models can be used
simultaneously, each with differing phases and orientations. If multiple
models are used the shapes and velocities are superimposed.
The wave models are specified in the velocity boundary condition. The
phase fraction boundary condition and the set utility both look up the
velocity condition in order to access the wave model. A velocity
boundary may be specified as follows:
inlet
{
type waveVelocity;
origin (0 0 0);
direction (1 0 0);
speed 2;
waves
(
Airy
{
length 300;
amplitude 2.5;
depth 150;
phase 0;
angle 0;
}
);
scale table ((1200 1) (1800 0));
crossScale constant 1;
}
The alpha boundary only requires the type, unless the name of the
velocity field is non-standard, in which case a "U" entry will also be
needed. The setWaves utility does not require a dictionary file; non-
standard field names can be specified as command-line arguments.
Wave models currently available are Airy (1st order) and Stokes2 (second
order). If a depth is specified, and it is not too large, then shallow
terms will be included, otherwise the models assume that the liquid is
deep.
This work was supported by Jan Kaufmann and Jan Oberhagemann at DNV GL.
discontinuous fields, with the discontinuity defined by a level set. The
functions do a proper integration of the discontinuous fields by tet-
and tri-cutting along the plane of the level set.
