It is now possible to define coordinate systems in a central location and
selected them by name for any model requiring one, e.g. the
explicitPorositySource.
Description
Provides a centralized coordinateSystem collection.
For example with the porous region specified in \c constant/fvOptions as
\verbatim
porosity
{
type explicitPorositySource;
explicitPorositySourceCoeffs
{
selectionMode cellZone;
cellZone porousBlockage;
type DarcyForchheimer;
// D 100; // Very little blockage
// D 200; // Some blockage but steady flow
// D 500; // Slight waviness in the far wake
D 1000; // Fully shedding behavior
d ($D $D $D);
f (0 0 0);
coordinateSystem porousBlockage;
}
}
\endverbatim
the corresponding coordinate system \c porousBlockage is looked-up
automatically from the \c constant/coordinateSystems dictionary:
\verbatim
porousBlockage
{
type cartesian;
origin (0 0 0);
coordinateRotation
{
type axesRotation;
e1 (1 0 0);
e2 (0 1 0);
}
}
\endverbatim
See \c tutorials/incompressible/pisoFoam/laminar/porousBlockage
such that div(q()) = divq(...)
and div(j()) = divj(...)
to unsure consistency between the reported heat (e.g. by the wallHeatFlux
functionObject) and mass fluxes and those used in the energy and specie
mass-fraction equations.
and changed to be an energy implicit correction to a temperature gradient
based heat-flux. This formulation is both energy conservative and temperature
consistent.
The wallHeatFlux functionObject has been updated to use a consistent heat-flux
from the heSolidThermo.
Fourier, eddyDiffusivity and nonUnityLewisEddyDiffusivity thermophysical
transport models now apply an implicit energy correction to a temperature
gradient based heat-flux to provide computational stability and efficiency while
converging to temperature gradient based solution. This ensures consistent heat
exchange between fluid and solid regions in CHT cases and with heat-flux
boundaries.
The Fourier and eddyDiffusivity models support single specie systems only
whereas nonUnityLewisEddyDiffusivity supports specie diffusion with independent
specification of turbulent Prandtl and Schmidt numbers, i.e. non-unity Lewis
number.
The unityLewisFourier and unityLewisEddyDiffusivity thermophysical transport
models use an implicit energy gradient based heat-flux which is optimal for
numerical stability and convergence but does not guarantee consistent heat
exchange between fluid and solid regions and heat-flux boundaries in the
presence of gradients of heat capacity. Both of these models support specie
diffusion with the restriction that the laminar and turbulent Prandtl and
Schmidt numbers are equal, i.e. unity Lewis number.
The thermophysical transport model is specified in the optional
thermophysicalTransport dictionary; if this file is not present the
unityLewisFourier model is selected for laminar and unityLewisEddyDiffusivity
for turbulent cases for backward compatibility.
The chtMultiRegionFoam tutorial cases have been updated to use the most
appropriate of the new thermophysical transport models.
so that foamDictionary conveniently supports the same format as the #includeFunc
argument list, e.g.
foamDictionary -set 'fieldAverage(U, p, prime2Mean = yes)' fieldAverage
The unnamed field arguments 'U' and 'p' are ignored by foamDictionary.
The field evaluations have been optimised using an additional
fieldInterpolation base class so that a virtual call happens only once
per field. This is the same pattern as that used to optimise Function1.
The vtk libraries are not fully independent of the paraview
installation, so in order to have multiple valid compilations of the
PVReaders (which is useful for testing) we need multiple versions of
these libraries, too. So, these libraries have been put into
$PV_PLUGIN_PATH, which is a paraview-version-specific subdirectory of
$FOAM_LIBBIN.
This tutorial demonstrates the use of the population balance modeling
capability of multiphaseEulerFoam for the case of a vertical pipe. It
superseeds all bubbleColumnPolydisperse cases, which have been removed.
Patch contributed by Institute of Fluid Dynamics,
Helmholtz-Zentrum Dresden - Rossendorf (HZDR)
All heat transfers that result from mass-transfer are now implemented in
terms of sensible enthalpy, so that they are consistent regardless of
which form of energy is being solved for. This has removed some spurious
temperature anomalies from a number of cases involving mass-transfer.
All heat transfers that result from mass-transfer are now linearised. In
the case of multi-specie systems this requires the specification of a
residual mass fraction, which is given by a new "residualY" keyword in
the constant/phaseProperties dictionary. If this entry is omitted for
multi-specie systems then linearisation is deactivated.
**** Details for developers ****
Methods have been added to the base heat transfer phase systems to
permit energy transfer as a result of phase change, without coupling to
a diffusive heat transfer model. These functions require a "weight" to
be specified in the call to define how the latent heat is divided
between either side of the interface. A weight of 0 indicates that the
latent heat is dissipated entirely in the upwind phase, and 1 means it
is entirely in the downwind phase.
The forms of latent heat calculation and transfer have been standardised
between the various phase systems. There are now two methods of
calculating the latent heat, and two methods of applying the transfer
(see below for details). These options are currently hard-coded into the
systems that use them, but they could be made user modifiable
per-mass-transfer in future.
Interface temperatures are now stored by the derived phase systems
alongside their corresponding mass transfer rates. These temperatures
are passed by argument to the phase-change heat transfer methods
provided by the base heat transfer systems. This allows multiple
mechanisms of mass transfer each involving different interface state to
occur across the same interface.
These changes have allowed all phase systems to use the same set of
base energy-transfer functionality.
**** Even more details for developers ****
The two forms of latent heat scheme available are:
symmetric: The latent heat is calculated as the difference between
the interface enthalpies on either side of an interface.
This is the simplest form.
upwind: The latent heat is calculated as the difference between
the bulk enthalpy on the side of the interface that mass
is being transferred from and the interface enthalpy on
the side of the interface that mass is transferring to.
This form may confer some stability benefits.
The two format of latent heat transfer are:
heat: The latent heat is applied by transferring heat unequally
on either side of an interface using the difference
between the bulk phase temperatures and the interface
temperature. No explicit latent heat source is required.
This method has a stability advantage over the "mass"
option, but the transfer is not energy conservative
unless the interface temperature is exactly correct.
mass: The latent heat is applied as an explicit mass transfer
source to both sides of an interface. The ratio between
the heat transfer coefficients on either side determines
what proportion of the latent heat source ends up in each
phase. Heat transfer is calculated equally on both sides
of an interface using bulk phase temperatures and is not
coupled to the thermal effect of phase change. This
method has the advantage of being energy conservative
even if the interface temperature is not exact, but it is
less stable than the "heat" option at extreme conditions.
