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.
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.
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
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.
For example in the potentialFreeSurfaceFoam/oscillatingBox tutorial it is
cleaner to apply the "linearRamp" function to the "sine" function rather than
using an amplitude table:
floatingObject
{
type fixedNormalInletOutletVelocity;
fixTangentialInflow false;
normalVelocity
{
type uniformFixedValue;
uniformValue
{
type scale;
value
{
type sine;
frequency 1;
amplitude 0.025;
scale (0 1 0);
level (0 0 0);
}
scale
{
type linearRamp;
duration 10;
}
}
}
value uniform (0 0 0);
}
coupled patches, to prevent rebound/stick/etc... on these patches. Also
added "none" interaction type to LocalInteraction, which reverts the
patch interaction to the fundamental behaviour. This is primarily useful
for non-coupled constraint types.
Resolves https://bugs.openfoam.org/view.php?id=2458
The pitzDaily case uses a lot of mesh grading close to walls and the shear layer.
Prior to v2.4, blockMesh only permitted grading in one direction within a single block,
so the pitzDaily mesh comprised of 13 blocks to accommodate the complex grading pattern.
blockMesh has multi-grading that allows users to divide a block in a given direction and
apply different grading within each division. The mesh generated with blockMesh using
13 blocks has been replaced with a mesh of 5 blocks that use multi-grading. The new
blockMeshDict configuration produces a mesh very similar to the original 13-block mesh.
including support for TDAC and ISAT for efficient chemistry calculation.
Description
Eddy Dissipation Concept (EDC) turbulent combustion model.
This model considers that the reaction occurs in the regions of the flow
where the dissipation of turbulence kinetic energy takes place (fine
structures). The mass fraction of the fine structures and the mean residence
time are provided by an energy cascade model.
There are many versions and developments of the EDC model, 4 of which are
currently supported in this implementation: v1981, v1996, v2005 and
v2016. The model variant is selected using the optional \c version entry in
the \c EDCCoeffs dictionary, \eg
\verbatim
EDCCoeffs
{
version v2016;
}
\endverbatim
The default version is \c v2015 if the \c version entry is not specified.
Model versions and references:
\verbatim
Version v2005:
Cgamma = 2.1377
Ctau = 0.4083
kappa = gammaL^exp1 / (1 - gammaL^exp2),
where exp1 = 2, and exp2 = 2.
Magnussen, B. F. (2005, June).
The Eddy Dissipation Concept -
A Bridge Between Science and Technology.
In ECCOMAS thematic conference on computational combustion
(pp. 21-24).
Version v1981:
Changes coefficients exp1 = 3 and exp2 = 3
Magnussen, B. (1981, January).
On the structure of turbulence and a generalized
eddy dissipation concept for chemical reaction in turbulent flow.
In 19th Aerospace Sciences Meeting (p. 42).
Version v1996:
Changes coefficients exp1 = 2 and exp2 = 3
Gran, I. R., & Magnussen, B. F. (1996).
A numerical study of a bluff-body stabilized diffusion flame.
Part 2. Influence of combustion modeling and finite-rate chemistry.
Combustion Science and Technology, 119(1-6), 191-217.
Version v2016:
Use local constants computed from the turbulent Da and Re numbers.
Parente, A., Malik, M. R., Contino, F., Cuoci, A., & Dally, B. B.
(2016).
Extension of the Eddy Dissipation Concept for
turbulence/chemistry interactions to MILD combustion.
Fuel, 163, 98-111.
\endverbatim
Tutorials cases provided: reactingFoam/RAS/DLR_A_LTS, reactingFoam/RAS/SandiaD_LTS.
This codes was developed and contributed by
Zhiyi Li
Alessandro Parente
Francesco Contino
from BURN Research Group
and updated and tested for release by
Henry G. Weller
CFD Direct Ltd.
to provide smoother behavior on start-up when an acceleration impulse is
applied, e.g. if the body is suddenly released. e.g.
dynamicFvMesh dynamicMotionSolverFvMesh;
motionSolverLibs ("librigidBodyMeshMotion.so");
solver rigidBodyMotion;
rigidBodyMotionCoeffs
{
report on;
solver
{
type Newmark;
}
ramp
{
type quadratic;
start 0;
duration 10;
}
.
.
.
will quadratically ramp the forces from 0 to their full values over the first
10s of the run starting from 0. If the 'ramp' entry is omitted no force ramping
is applied.
Description
Ramp function base class for the set of scalar functions starting from 0 and
increasing monotonically to 1 from \c start over the \c duration and
remaining at 1 thereafter.
Usage:
\verbatim
<entryName> <rampFunction>;
<entryName>Coeffs
{
start 10;
duration 20;
}
\endverbatim
or
\verbatim
<entryName>
{
type <rampFunction>;
start 10;
duration 20;
}
\endverbatim
Where:
\table
Property | Description | Required | Default value
start | Start time | no | 0
duration | Duration | yes |
\endtable
The following common ramp functions are provided: linear, quadratic, halfCosine,
quarterCosine and quaterSine, others can easily be added and registered to the run-time
selection system.
e.g.
ramp
{
type quadratic;
start 200;
duration 1.6;
}
but the old format is supported for backward compatibility:
ramp linear;
rampCoeffs
{
start 200;
duration 1.6;
}
