XiEngineFoam is a premixed/partially-premixed combustion engine solver which
exclusively uses the Xi flamelet combustion model.
engineFoam is a general engine solver for inhomogeneous combustion with or
without spray supporting run-time selection of the chemistry-based combustion
model.
To unsure fvOptions are instantiated for post-processing createFvOptions.H must
be included in createFields.H rather than in the solver directly.
Resolves bug-report https://bugs.openfoam.org/view.php?id=2733
BUG: porousSimpleFoam: moved createFvOptions.H into createFields.H for -postProcess option
Resolves bug-report https://bugs.openfoam.org/view.php?id=2733
BUG: solvers: Moved fvOption construction into createFields.H for post-processing
This ensures that the fvOptions are constructed for the -postProcessing option
so that functionObjects which process fvOption data operate correctly in this
mode.
XiEngineFoam is a premixed/partially-premixed combustion engine solver which
exclusively uses the Xi flamelet combustion model.
engineFoam is a general engine solver for inhomogeneous combustion with or
without spray supporting run-time selection of the chemistry-based combustion
model.
- controlled by the the 'printExecutionFormat' InfoSwitch in
etc/controlDict
// Style for "ExecutionTime = " output
// - 0 = seconds (with trailing 's')
// - 1 = day-hh:mm:ss
ExecutionTime = 112135.2 s ClockTime = 113017 s
ExecutionTime = 1-07:08:55.20 ClockTime = 1-07:23:37
- Callable via the new Time::printExecutionTime() method,
which also helps to reduce clutter in the applications.
Eg,
runTime.printExecutionTime(Info);
vs
Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
<< " ClockTime = " << runTime.elapsedClockTime() << " s"
<< nl << endl;
--
ENH: return elapsedClockTime() and clockTimeIncrement as double
- previously returned as time_t, which is less portable.
- when constructing dimensioned fields that are to be zero-initialized,
it is preferrable to use a form such as
dimensionedScalar(dims, Zero)
dimensionedVector(dims, Zero)
rather than
dimensionedScalar("0", dims, 0)
dimensionedVector("zero", dims, vector::zero)
This reduces clutter and also avoids any suggestion that the name of
the dimensioned quantity has any influence on the field's name.
An even shorter version is possible. Eg,
dimensionedScalar(dims)
but reduces the clarity of meaning.
- NB: UniformDimensionedField is an exception to these style changes
since it does use the name of the dimensioned type (instead of the
regIOobject).
- in many cases can just use lookupOrDefault("key", bool) instead of
lookupOrDefault<bool> or lookupOrDefault<Switch> since reading a
bool from an Istream uses the Switch(Istream&) anyhow
STYLE: relocated Switch string names into file-local scope
e.g. (fvc::interpolate(HbyA) & mesh.Sf()) -> fvc::flux(HbyA)
This removes the need to create an intermediate face-vector field when
computing fluxes which is more efficient, reduces the peak storage and
improved cache coherency in addition to providing a simpler and cleaner
API.
The boundary conditions of HbyA are now constrained by the new "constrainHbyA"
function which applies the velocity boundary values for patches for which the
velocity cannot be modified by assignment and pressure extrapolation is
not specified via the new
"fixedFluxExtrapolatedPressureFvPatchScalarField".
The new function "constrainPressure" sets the pressure gradient
appropriately for "fixedFluxPressureFvPatchScalarField" and
"fixedFluxExtrapolatedPressureFvPatchScalarField" boundary conditions to
ensure the evaluated flux corresponds to the known velocity values at
the boundary.
The "fixedFluxPressureFvPatchScalarField" boundary condition operates
exactly as before, ensuring the correct flux at fixed-flux boundaries by
compensating for the body forces (gravity in particular) with the
pressure gradient.
The new "fixedFluxExtrapolatedPressureFvPatchScalarField" boundary
condition may be used for cases with or without body-forces to set the
pressure gradient to compensate not only for the body-force but also the
extrapolated "HbyA" which provides a second-order boundary condition for
pressure. This is useful for a range a problems including impinging
flow, extrapolated inlet conditions with body-forces or for highly
viscous flows, pressure-induced separation etc. To test this boundary
condition at walls in the motorBike tutorial case set
lowerWall
{
type fixedFluxExtrapolatedPressure;
}
motorBikeGroup
{
type fixedFluxExtrapolatedPressure;
}
Currently the new extrapolated pressure boundary condition is supported
for all incompressible and sub-sonic compressible solvers except those
providing implicit and tensorial porosity support. The approach will be
extended to cover these solvers and options in the future.
Note: the extrapolated pressure boundary condition is experimental and
requires further testing to assess the range of applicability,
stability, accuracy etc.
Henry G. Weller
CFD Direct Ltd.
fvOptions are transferred to the database on construction using
fv::options::New which returns a reference. The same function can be
use for construction and lookup so that fvOptions are now entirely
demand-driven.
The abstract base-classes for fvOptions now reside in the finiteVolume
library simplifying compilation and linkage. The concrete
implementations of fvOptions are still in the single monolithic
fvOptions library but in the future this will be separated into smaller
libraries based on application area which may be linked at run-time in
the same manner as functionObjects.
Provides run-time selection of buoyancy sources for compressible solvers
Replaces the built-in buoyancy sources in XiFoam, reactingFoam and
rhoReactingFoam.
e.g. in constant/fvOptions specify
momentumSource
{
type buoyancyForce;
buoyancyForceCoeffs
{
fieldNames (U);
}
}
and optionally specify the buoyancy energy source in the enthalpy
equation:
energySource
{
type buoyancyEnergy;
buoyancyEnergyCoeffs
{
fieldNames (h);
}
}
or internal energy equation
energySource
{
type buoyancyEnergy;
buoyancyEnergyCoeffs
{
fieldNames (e);
}
}
XiDyMFoam : compressible version of XiFoam
oscillatingCylinder : 2D case with cylinder moving up and down
annularCombustorTurbine : part of 3D combuster using cyclicPeriodicAMI
fvOptions does not have the appropriate structure to support MRF as it
is based on option selection by user-specified fields whereas MRF MUST
be applied to all velocity fields in the particular solver. A
consequence of the particular design choices in fvOptions made it
difficult to support MRF for multiphase and it is easier to support
frame-related and field related options separately.
Currently the MRF functionality provided supports only rotations but
the structure will be generalized to support other frame motions
including linear acceleration, SRF rotation and 6DoF which will be
run-time selectable.
The old separate incompressible and compressible libraries have been removed.
Most of the commonly used RANS and LES models have been upgraded to the
new framework but there are a few missing which will be added over the
next few days, in particular the realizable k-epsilon model. Some of
the less common incompressible RANS models have been introduced into the
new library instantiated for incompressible flow only. If they prove to
be generally useful they can be templated for compressible and
multiphase application.
The Spalart-Allmaras DDES and IDDES models have been thoroughly
debugged, removing serious errors concerning the use of S rather than
Omega.
The compressible instances of the models have been augmented by a simple
backward-compatible eddyDiffusivity model for thermal transport based on
alphat and alphaEff. This will be replaced with a separate run-time
selectable thermal transport model framework in a few weeks.
For simplicity and ease of maintenance and further development the
turbulent transport and wall modeling is based on nut/nuEff rather than
mut/muEff for compressible models so that all forms of turbulence models
can use the same wall-functions and other BCs.
All turbulence model selection made in the constant/turbulenceProperties
dictionary with RAS and LES as sub-dictionaries rather than in separate
files which added huge complexity for multiphase.
All tutorials have been updated so study the changes and update your own
cases by comparison with similar cases provided.
Sorry for the inconvenience in the break in backward-compatibility but
this update to the turbulence modeling is an essential step in the
future of OpenFOAM to allow more models to be added and maintained for a
wider range of cases and physics. Over the next weeks and months more
turbulence models will be added of single and multiphase flow, more
additional sub-models and further development and testing of existing
models. I hope this brings benefits to all OpenFOAM users.
Henry G. Weller
