The new "rigid" joint permits no motion at all, "function" specifies the
position of the joint as a function of the position of it's parent, and
"functionDot" specifies the position of the joint as a function of the
velocity of it's parent. Note that the functions are applied uniformly
to each component of the parent joint's position/motion. Example
specifications are shown below.
joint
{
type rigid;
}
joint
{
type function;
function table ((-1 0) (0 1) (1 0));
}
joint
{
type functionDot;
function table ((-1 0) (0 1) (1 0));
}
This work was supported by Caitlin Worden Hodge, at Zyba
This allows for fixed joints or joints which completely constrain the
motion as a function of some other aspect of the model. The latter has
also been facilitaed by adding a reference to the rigid body model to
the base joint class.
Now lnInclude are created as required by the presence of entries in the EXE_INC
variable in the Make/options file. This removes the need for calling
wmakeLnInclude in various Allwmake files to ensure the existence of the
lnInclude directories prior to compilation of dependent libraries.
Requires the following changes to the corresponding entry in the fvOptions dictionary:
i. Use Tsol instead Tmelt as previously to define melting temperature in
isothermal phase change (for pure substance or eutectic mixture -> Tsol = Tliq);
ii. Optionally define new Tliq > Tsol to consider liquidus temperature in
non-isothermal phase change (for miscible mixture), where previous
defined Tsol defines solidus temperature;
iii. optionally define also alpha1e to consider max eutectic melt
fraction (that should be the percentage of solvent phase changed from
initial to eutectic liquid concentration) in partially isothermal (at
Tsol=Teutectic) and non-isothermal (from Tsol=Teutectic to Tliq) phase
change (for solid not miscible mixture) (alpha1e=0 -> pure substance;
alpha1e=1 -> eutectic mixture that is strictely not permitted).
Description
This source is designed to model the effect of solidification and melting
processes, e.g. windhield defrosting.
The isotherm phase change occurs at the melting temperature, \c Tsol (= \c
Tliq). The not isotherm phase change occurs between solidus and liquidus
temperature, \c Tsol < \c Tliq respectively, as long as the melt fraction is
greater than the max eutectic melt fraction, \c alpha1e (0 =
pure_substance, 1 = eutectic_mixture is not permitted) , i.e. eutectic to
initial solvent concentration difference, where a linear eutectic melt
fraction to temperature relation is considered - lever rule.
The presence of the solid phase in the flow field is incorporated into the
model as a momentum porosity contribution; the energy associated with the
phase change is added as an enthalpy contribution.
References:
\verbatim
Voller, V. R., & Prakash, C. (1987).
A fixed grid numerical modelling methodology for convection-diffusion
mushy region phase-change problems.
International Journal of Heat and Mass Transfer, 30(8), 1709-1719.
Swaminathan, C. R., & Voller, V. R. (1992).
A general enthalpy method for modeling solidification processes.
Metallurgical transactions B, 23(5), 651-664.
\endverbatim
The model generates the field \c \<name\>:alpha1 which can be visualised to
to show the melt distribution as a fraction [0-1].
Usage
Example usage:
\verbatim
solidificationMeltingSource1
{
type solidificationMeltingSource;
active yes;
selectionMode cellZone;
cellZone iceZone;
Tsol 273;
L 334000;
thermoMode thermo;
beta 50e-6;
rhoRef 800;
}
\endverbatim
Where:
\table
Property | Description | Required | Default value
Tsol | Solidus temperature [K] | yes |
Tliq | Liquidus temperature [K] | no | Tsol
alpha1e | Max eutectic melt fraction [0-1[ | no | 0
L | Latent heat of fusion [J/kg] | yes |
relax | Relaxation coefficient [0-1] | no | 0.9
thermoMode | Thermo mode [thermo|lookup] | yes |
rhoRef | Reference (solid) density [kg/m^3] | yes |
rho | Name of density field | no | rho
T | Name of temperature field | no | T
Cp | Name of specific heat field | no | Cp
U | Name of velocity field | no | U
phi | Name of flux field | no | phi
Cu | Model coefficient [1/s] | no | 100000
q | Model coefficient | no | 0.001
beta | Thermal expansion coefficient [1/K] | yes |
g | Accelerartion due to gravity | no |
\endtable
Patch contributed by Lorenzo Trevisan and integrated by CFD Direct.
Resolves patch request https://bugs.openfoam.org/view.php?id=2907
This change ensures only one include file is open at a time by storing the
included files on a dynamic list rather than scanning the tree and holding a
list of open buffers. This new approach is a bit faster and avoids the "too
many open files" error on machines with low limits on the number of file
descriptors allocated to users.
A new constraint patch has been added which permits AMI coupling in
cyclic geometries. The coupling is repeated with different multiples of
the cyclic transformation in order to achieve a full correspondence.
This allows, for example, a cylindrical AMI interface to be used in a
sector of a rotational geometry.
The patch is used in a similar manner to cyclicAMI, except that it has
an additional entry, "transformPatch". This entry must name a coupled
patch. The transformation used to repeat the AMI coupling is taken from
this patch. For example, in system/blockMeshDict:
boundary
(
cyclic1
{
type cyclic;
neighbourPatch cyclic2;
faces ( ... );
}
cyclic2
{
type cyclic;
neighbourPatch cyclic1;
faces ( ... );
}
cyclicRepeatAMI1
{
type cyclicRepeatAMI;
neighbourPatch cyclicRepeatAM2;
transformPatch cyclic1;
faces ( ... );
}
cyclicRepeatAMI2
{
type cyclicRepeatAMI;
neighbourPatch cyclicRepeatAMI1;
transformPatch cyclic1;
faces ( ... );
}
// other patches ...
);
In this example, the transformation between cyclic1 and cyclic2 is used
to define the repetition used by the two cyclicRepeatAMI patches.
Whether cyclic1 or cyclic2 is listed as the transform patch is not
important.
A tutorial, incompressible/pimpleFoam/RAS/impeller, has been added to
demonstrate the functionality. This contains two repeating AMI pairs;
one cylindrical and one planar.
A significant amount of maintenance has been carried out on the AMI and
ACMI patches as part of this work. The AMI methods now return
dimensionless weights by default, which prevents ambiguity over the
units of the weight field during construction. Large amounts of
duplicate code have also been removed by deriving ACMI classes from
their AMI equivalents. The reporting and writing of AMI weights has also
been unified.
This work was supported by Dr Victoria Suponitsky, at General Fusion
Solution controls now detect when convergence occurs at a write time and
avoid writing the final directory twice. This also resolves the issue
whereby a purgeWrite setting would remove an extra directory.
This resolves bug report https://bugs.openfoam.org/view.php?id=2904
Added a function object for the reacting Euler-Euler solvers which
evaluates and writes out the blended interfacial forces acting on a
given phase (drag, virtual mass, lift, wall lubrication and turbulent
dispersion).
Patch contributed by Institute of Fluid Dynamics, Helmholtz-Zentrum
Dresden - Rossendorf (HZDR)
The Sauter mean diameter calculation has been modified to be more stable
in the limit of vanishing phase fraction. The calculation of the overall
Sauter mean diameter for a populationBalance involving more than one
velocityGroup has been removed. This calculation depends upon the phase
fraction and it is not stable as the fractions tend to zero. The overall
Sauter mean diameter is only used for post-processing and can still be
recovered from the individual diameter fields of the involved
velocityGroups.
Some parts of the population balance modeling have also been renamed and
refactored.
Patch contributed by Institute of Fluid Dynamics, Helmholtz-Zentrum
Dresden - Rossendorf (HZDR)
Surfaces are specified as a list and the controls applied to each, e.g. in the
rhoPimpleFoam/RAS/annularThermalMixer tutorial:
surfaces
(
"AMI.obj"
"shaft.obj"
"wall.obj"
"statorBlades.obj"
"rotorBlades.obj"
);
includedAngle 150; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 10; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
If different controls are required for different surfaces multiple
sub-dictionaries can be used:
AMIsurfaces
{
surfaces
(
"AMI.obj"
);
includedAngle 140; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 8; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
}
otherSurfaces
{
surfaces
(
"shaft.obj"
"wall.obj"
"statorBlades.obj"
"rotorBlades.obj"
);
includedAngle 150; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 10; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
}
Existing feature edge files corresponding to particular surfaces can be specified using
the "files" association list:
surfaces
(
"AMI.obj"
"shaft.obj"
"wall.obj"
"statorBlades.obj"
"rotorBlades.obj"
);
files
(
"AMI.obj" "constant/triSurface/AMI.obj.eMesh";
);
includedAngle 150; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 10; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
An "inletOutlet" switch has been added to the wave velocity boundary
condition to allow the boundary to be fixed, as is possible for the
corresponding alpha condition.
A "heightAboveWave" option has been added to the wave superposition
class to calculate velocity based on the height above the wave, rather
than above the origin. This may improve initialisation but it may also
generate divergence in the initial velocity field.
The alpha condition has also been completed so that it applies a
modelled gradient when the flow points out and a wave pressure condition
is in use.
fvcAverage and fvcReconstruct both do divisions or inverses of surface
summed fields. A single-cell zero-dimension case, has no genuine faces
on which to sum, so surface sums are identically zero. This change
detects this situation and returns a zero value instead of failing due
to a divide by zero.
This allows the multiphase test cases to be reduced to just one cell.
to avoid the need for sed'ing the output. This improves performance by avoiding
the need for calling additional commands and generating a temporary file.
