The patchType override logic has been simplified and made consistent
between fv, fvs and point patch fields. The "constraintType" attribute
has been removed from point fields as it was not being used.
This change fixes failures that occur with the mapping of fields with
patchType overrides. It fixes a crash that previously occurred when
redistributing patch fields with patchType overrides. It also makes
decomposition correctly maintain patchType overrides on cyclics when
those cyclics are separated and become processorCyclics.
These fixes have been achieved by removing the patchType override data
from the fv and point patches. Whether or not the field overrides the
underlying patchType constraint is now determined on the fly from the
patch and field names and what is available on the field run-time
selection table.
to differentiate between flux field which require face-flipping and
non-extensive surface fields which do not. Currently flux fields are
distinguished by being surfaceScalarField with dimensions of either volumetric
or mass flux.
This change corrects the handling of the surfaceVectorField Uf which was
previously mapped incorrectly on faces requiring the flipping of the flux
orientation.
This new constraint type is preferable to the 'empty' type used previously as it
support patch field values for post-processing and other purposes.
The internalFvPatchField operates as a 'zeroGradient' type so that the adjacent
cell values are displayed on the faces exposed by the sub-setting.
The internalFvsPatchField operates as a 'calculated' type so that the internal
face values are displayed on the faces exposed by the sub-setting.
The immediate benefit of this change can be seen when using 'subsetMesh' without
the '-noFields' option to create and write a sub-set of an 'fvMesh' with field
values, now the face values of the 'exposed' internal faces can be visualised.
TableBase, TableFile and Table now combined into a single simpler Table class
which handle both the reading of embedded and file data using the generalised
TableReader. The new EmbeddedTableReader handles the embedded data reading
providing the functionality of the original Table class within the same
structure that can read the data from separate files.
The input format defaults to 'embedded' unless the 'file' entry is present and
the Table class is added to the run-time selection table under the name 'table'
and 'tableFile' which provides complete backward comparability. However it is
advisable to migrate cases to use the new 'table' entry and all tutorial cases
have been updated.
While calculatedFvPatchField would be considered as a BC which fixes the value
during solution it cannot be used for that purpose and under all other
conditions it does not fix the boundary value as the '=' operator changes the
value. However calculatedFvPatchField is used for the reference phase in
multiphase systems and if it is considered to fix the boundary value it interferes
with the operation of the MULES limiter and hence it is far preferable if it
does not fix the value.
providing the shear-stress term in the momentum equation for incompressible and
compressible Newtonian, non-Newtonian and visco-elastic laminar flow as well as
Reynolds averaged and large-eddy simulation of turbulent flow.
The general deviatoric shear-stress term provided by the MomentumTransportModels
library is named divDevTau for compressible flow and divDevSigma (sigma =
tau/rho) for incompressible flow, the spherical part of the shear-stress is
assumed to be either included in the pressure or handled separately. The
corresponding stress function sigma is also provided which in the case of
Reynolds stress closure returns the effective Reynolds stress (including the
laminar contribution) or for other Reynolds averaged or large-eddy turbulence
closures returns the modelled Reynolds stress or sub-grid stress respectively.
For visco-elastic flow the sigma function returns the effective total stress
including the visco-elastic and Newtonian contributions.
For thermal flow the heat-flux generated by thermal diffusion is now handled by
the separate ThermophysicalTransportModels library allowing independent run-time
selection of the heat-flux model.
During the development of the MomentumTransportModels library significant effort
has been put into rationalising the components and supporting libraries,
removing redundant code, updating names to provide a more logical, consistent
and extensible interface and aid further development and maintenance. All
solvers and tutorials have been updated correspondingly and backward
compatibility of the input dictionaries provided.
Henry G. Weller
CFD Direct Ltd.
These provide pressure boundary conditions suitable for use on
boundaries where the flow may reverse or on which the inlet or outlet
state is not known or well defined. The condition takes the following
form:
p = p0 + 0.5*Un*mag(Un)
In the case of exactly normal inlet velocity, this condition sets the
same pressure as the totalPressure condition. The pressure that is set
increases with increasing outlet velocity and decreases with increasing
inlet velocity. This makes it self-limiting and extremely stable in a
number of configurations which were not easily simulated previously. The
condition also does varies smoothly as the flux reverses, which also
aids stability.
The controls of this boundary condition are exactly the same as for the
totalPressure condition. Note, however, that "p0" is not necessarily the
total pressure any more. It is, in general, a reference pressure.
An example usage is as follows:
sides
{
type entrainmentPressure;
p0 100;
}
Rather than being tied to the Time class the dlLibraryTable libs is now a global
variable in the Foam namespace which is accessable by any class needing to load
dynamic libraries, in particular argList, Time and codeStream.
A single transformer object is now maintained within cyclic patches and returned
from a single virtual functions massively simplifying the interface and allowing
for further rationalisation of the calculation of the transformation.
The implementation of the optional non-uniform transformations in coupled
patches was based on transform property lists which could be either length 0 for
no transformation, 1 for uniform transformation or n-faces for non-uniform
transformation. This complexity was maintenance nightmare but kept to support
the hack in the original film implementation to partially work around the
conservation error. Now that film has been re-implemented in fully mass
conservative form this unphysical non-uniform transformation support is no
longer needed and the coupled patch transformations have been completely
refactored to be simpler and more rational with single values for the
transformation properties and boolians to indicate which transformations are
needed.
All of the film transport equations are now formulated with respect to the film
volume fraction in the region cell layer rather than the film thickness which
ensures mass conservation of the film even as it flows over curved surfaces and
around corners. (In the previous formulation the conservation error could be as
large as 15% for a film flowing around a corner.)
The film Courant number is now formulated in terms of the film cell volumetric
flux which avoids the stabilised division by the film thickness and provides a
more reliable estimate for time-step evaluation. As a consequence the film
solution is substantially more robust even though the time-step is now
significantly higher. For film flow dominated problem the simulations now runs
10-30x faster.
The inconsistent extended PISO controls have been replaced by the standard
PIMPLE control system used in all other flow solvers, providing consistent
input, a flexible structure and easier maintenance.
The momentum corrector has been re-formulated to be consistent with the momentum
predictor so the optional PIMPLE outer-corrector loop converges which it did not
previously.
nonuniformTransformCyclic patches and corresponding fields are no longer needed
and have been removed which paves the way for a future rationalisation of the
handling of cyclic transformations in OpenFOAM to improve robustness, usability
and maintainability.
Film sources have been simplified to avoid the need for fictitious boundary
conditions, in particular mappedFixedPushedInternalValueFvPatchField which has
been removed.
Film variables previously appended with an "f" for "film" rather than "face"
have been renamed without the unnecessary and confusing "f" as they are
localised to the film region and hence already directly associated with it.
All film tutorials have been updated to test and demonstrate the developments
and improvements listed above.
Henry G. Weller
CFD Direct Ltd.
