To switch-off radiation set
radiationModel none;
in radiationProperties which instantiates "null" model that does not read any
data or coefficients or evaluate any fields.
The sampled sets have been renamed in a more explicit and consistent
manner, and two new ones have also been added. The available sets are as
follows:
arcUniform: Uniform samples along an arc. Replaces "circle", and
adds the ability to sample along only a part of the circle's
circumference. Example:
{
type arcUniform;
centre (0.95 0 0.25);
normal (1 0 0);
radial (0 0 0.25);
startAngle -1.57079633;
endAngle 0.52359878;
nPoints 200;
axis x;
}
boundaryPoints: Specified point samples associated with a subset of
the boundary. Replaces "patchCloud". Example:
{
type boundaryPoints;
patches (inlet1 inlet2);
points ((0 -0.05 0.05) (0 -0.05 0.1) (0 -0.05 0.15));
maxDistance 0.01;
axis x;
}
boundaryRandom: Random samples within a subset of the boundary.
Replaces "patchSeed", but changes the behaviour to be entirely
random. It does not seed the boundary face centres first. Example:
{
type boundaryRandom;
patches (inlet1 inlet2);
nPoints 1000;
axis x;
}
boxUniform: Uniform grid of samples within a axis-aligned box.
Replaces "array". Example:
{
type boxUniform;
box (0.95 0 0.25) (1.2 0.25 0.5);
nPoints (2 4 6);
axis x;
}
circleRandom: Random samples within a circle. New. Example:
{
type circleRandom;
centre (0.95 0 0.25);
normal (1 0 0);
radius 0.25;
nPoints 200;
axis x;
}
lineFace: Face-intersections along a line. Replaces "face". Example:
{
type lineFace;
start (0.6 0.6 0.5);
end (0.6 -0.3 -0.1);
axis x;
}
lineCell: Cell-samples along a line at the mid-points in-between
face-intersections. Replaces "midPoint". Example:
{
type lineCell;
start (0.5 0.6 0.5);
end (0.5 -0.3 -0.1);
axis x;
}
lineCellFace: Combination of "lineFace" and "lineCell". Replaces
"midPointAndFace". Example:
{
type lineCellFace;
start (0.55 0.6 0.5);
end (0.55 -0.3 -0.1);
axis x;
}
lineUniform: Uniform samples along a line. Replaces "uniform".
Example:
{
type lineUniform;
start (0.65 0.3 0.3);
end (0.65 -0.3 -0.1);
nPoints 200;
axis x;
}
points: Specified points. Replaces "cloud" when the ordered flag is
false, and "polyLine" when the ordered flag is true. Example:
{
type points;
points ((0 -0.05 0.05) (0 -0.05 0.1) (0 -0.05 0.15));
ordered yes;
axis x;
}
sphereRandom: Random samples within a sphere. New. Example:
{
type sphereRandom;
centre (0.95 0 0.25);
radius 0.25;
nPoints 200;
axis x;
}
triSurfaceMesh: Samples from all the points of a triSurfaceMesh.
Replaces "triSurfaceMeshPointSet". Example:
{
type triSurfaceMesh;
surface "surface.stl";
axis x;
}
The headers have also had documentation added. Example usage and a
description of the control parameters now exists for all sets.
In addition, a number of the algorithms which generate the sets have
been refactored or rewritten. This was done either to take advantage of
the recent changes to random number generation, or to remove ad-hoc
fixes that were made unnecessary by the barycentric tracking algorithm.
including third-body and pressure dependent derivatives, and derivative of the
temperature term. The complete Jacobian is more robust than the incomplete and
partially approximate form used previously and improves the efficiency of the
stiff ODE solvers which rely on the Jacobian.
Reaction rate evaluation moved from the chemistryModel to specie library to
simplfy support for alternative reaction rate expressions and associated
Jacobian terms.
Temperature clipping included in the Reaction class. This is inactive by default
but for most cases it is advised to provide temperature limits (high and
low). These are provided in the foamChemistryFile with the keywords Thigh and
Tlow. When using chemkinToFoam these values are set to the limits of the Janaf
thermodynamic data. With the new Jacobian this temperature clipping has proved
very beneficial for stability and for some cases essential.
Improvement of the TDAC MRU list better integrated in add and grow functions.
To get the most out of this significant development it is important to re-tune
the ODE integration tolerances, in particular the absTol in the odeCoeffs
sub-dictionary of the chemistryProperties dictionary:
odeCoeffs
{
solver seulex;
absTol 1e-12;
relTol 0.01;
}
Typically absTol can now be set to 1e-8 and relTol to 0.1 except for ignition
time problems, and with theses settings the integration is still robust but for
many cases a lot faster than previously.
Code development and integration undertaken by
Francesco Contino
Henry G. Weller, CFD Direct
runApplication isn't needed for foamDictionary as it doesn't log
anything of consequence. Using runApplication leads to false unconfirmed
completion warnings in the test loop as foamDictionary does not generate
an end statement.
The changeDictonary setup has been removed and replaced with a more
typical boundary condition setup. Dictionary variables and wildcards
have been used to reduce repetition of the simulation parameters.
The tutorial now also demonstrates how to run a multi-region CHT case
completely in parallel. If run-time post processing was being utilised
there would be no need for reconstruction at any point.
