Replaced the ad hoc geometric mean blending with the more physical wall distance
Reynolds number blending function.
Additionally the part of the production term active for y+ < 11.6 has been
reinstated.
Sets the boundary values of p_rgh corresponding to a constant density hydrostatic
pressure distribution.
Description
This boundary condition provides a hydrostatic pressure condition for p_rgh,
calculated as:
\f[
p_{rgh} = p_{ref} - (\rho - \rho_0) g (h - h_{ref})
\f]
where
\vartable
p_{rgh} | Pseudo hydrostatic pressure [Pa]
p_{ref} | Static pressure at hRef [Pa]
h | Height in the opposite direction to gravity
h_{ref} | Reference height in the opposite direction to gravity
\rho | Density field
\rho_{ref} | Uniform reference density at boundary
g | Acceleration due to gravity [m/s^2]
\endtable
Usage
\table
Property | Description | Required | Default value
pRef | Reference static pressure | yes |
rhoRef | Reference density | yes |
rho | Density field name | no | rho
\endtable
Example of the boundary condition specification:
\verbatim
<patchName>
{
type prghUniformDensityHydrostaticPressure;
rhoRef 1000;
p 0;
value uniform 0; // optional initial value
}
\endverbatim
Partial elimination has been implemented for the multiphase Euler-Euler
solver. This does a linear solution of the drag system when calculating
flux and velocity corrections after the solution of the pressure
equation. This can improve the behaviour of the solution in the event
that the drag coupling is high. It is controlled by means of a
"partialElimination" switch within the PIMPLE control dictionary in
fvSolution.
A re-organisation has also been done in order to remove the exposure of
the sub-modelling from the top-level solver. Rather than looping the
drag, virtual mass, lift, etc..., models directly, the solver now calls
a set of phase-system methods which group the different force terms.
These new methods are documented in MomentumTransferPhaseSystem.H. Many
other accessors have been removed as a consequence of this grouping.
A bug was also fixed whereby the face-based algorithm was not
transferring the momentum associated with a given interfacial mass
transfer.
Description
Evaluates and writes the turbulence intensity field 'I'.
The turbulence intensity field 'I' is the root-mean-square of the turbulent
velocity fluctuations normalised by the local velocity magnitude:
\f[
I \equiv \frac{\sqrt{\frac{2}{3}\, k}}{U}
\f]
To avoid spurious extrema and division by 0 I is limited to 1 where the
velocity magnitude is less than the turbulent velocity fluctuations.
Example of function object specification:
\verbatim
functions
{
.
.
.
turbulenceIntensity
{
type turbulenceIntensity;
libs ("libfieldFunctionObjects.so");
}
.
.
.
}
\endverbatim
or using the standard configuration file:
\verbatim
functions
{
.
.
.
#includeFunc turbulenceIntensity
.
.
.
}
\endverbatim
Minmod is the default limiter function and specified with an explicit name e.g.:
gradSchemes
{
default Gauss linear;
limited cellLimited Gauss linear 1;
}
Venkatakrishnan and cubic limiter functions are also provided and may be
specified explicitly e.g.:
gradSchemes
{
default Gauss linear;
limited cellLimited<Venkatakrishnan> Gauss linear 1;
}
or
gradSchemes
{
default Gauss linear;
limited cellLimited<cubic> 1.5 Gauss linear 1;
}
The standard minmod function is recommended for most applications but if
convergence or stability problems arise it may be beneficial to use one of the
alternatives which smooth the gradient limiting. The Venkatakrishnan is not
well formulated and allows the limiter to exceed 1 whereas the cubic limiter is
designed to obey all the value and gradient constraints on the limiter function,
see
Michalak, K., & Ollivier-Gooch, C. (2008).
Limiters for unstructured higher-order accurate solutions
of the Euler equations.
In 46th AIAA Aerospace Sciences Meeting and Exhibit (p. 776).
The cubic limiter function requires the transition point at which the limiter
function reaches 1 is an input parameter which should be set to a value between
1 and 2 although values larger than 2 are physical but likely to significantly
reduce the accuracy of the scheme.
These BCs blend between typical inflow and outflow conditions based on the
velocity orientation.
airFoil2D tutorial updated to demonstrate these new BCs.
Now if a <field> file does not exist first the compressed <field>.gz file is
searched for and if that also does not exist the <field>.orig file is searched
for.
This simplifies case setup and run scripts as now setField for example can read
the <field>.orig file directly and generate the <field> file from it which is
then read by the solver. Additionally the cleanCase function used by
foamCleanCase and the Allclean scripts automatically removed <field> files if
there is a corresponding <field>.orig file. So now there is no need for the
Allrun scripts to copy <field>.orig files into <field> or for the Allclean
scripts to explicitly remove them.
A lower limit of one on the number of particles represented by a single
parcel has been removed from the injection models. It may be appropriate
to simulate the statistical behaviour of a particulate flow with more
lagrangian elements than physical particles. A unity lower limit does
not permit this.
The limit was, in some situations, also causing the large-diameter end
of an injected distribution to be clipped.
This resolves bug report https://bugs.openfoam.org/view.php?id=2837
The logic governing function objects' ability to change the time-step
has been modified so that it is compatible with the time-step adjustment
done in the Time class. The behaviour has been split into a method which
sets the step directly, and another which moidifies the time until the
next write operation (i.e., the time that the solver "aims" for).
This fixes an issue where the adjustments in Time and the function
objects interfere and cause the time step to decrease exponentially down
to machine precision. It also means that the set-time-step function
object now does not break the adjustable run-time setting.
This resolves bug report https://bugs.openfoam.org/view.php?id=2820
Splitting MPI_COMM_FOAM from MPI_COMM_WORLD allows OpenFOAM to be linked with
other libraries communicating via MPI.
Resolves feature request https://bugs.openfoam.org/view.php?id=2815
The solution controls have been rewritten for use in multi-region
solvers, and PIMPLE fluid/solid solution controls have been implemented
within this framework.
PIMPLE also now has time-loop convergence control which can be used to
end the simulation once a certain initial residual is reached. This
allows a PIMPLE solver to run with equivalent convergence control to a
SIMPLE solver. Corrector loop convergence control is still available,
and can be used at the same time as the time-loop control.
The "residualControl" sub-dictionary of PIMPLE contains the residual
values required on the first solve of a time-step for the simulation to
end. This behaviour is the same as SIMPLE. The
"outerCorrectorResidualControl" sub-dictionary contains the tolerances
required for the corrector loop to exit. An example specification with
both types of control active is shown below.
PIMPLE
{
// ...
residualControl
{
p 1e-3;
U 1e-4;
"(k|epsilon|omega)" 1e-3;
}
outerCorrectorResidualControl
{
U
{
tolerance 1e-4;
relTol 0.1;
}
"(k|epsilon|omega)"
{
tolerance 1e-3;
relTol 0.1;
}
}
}
Note that existing PIMPLE "residualControl" entries will need to be
renamed "outerCorrectorResidualControl".
Application within a solver has also changed slightly. In order to have
convergence control for the time loop as a whole, the
solutionControl::loop(Time&) method (or the equivalent run method) must
be used; i.e.,
while (simple.loop(runTime))
{
Info<< "Time = " << runTime.timeName() << nl << endl;
// solve ...
}
or,
while (pimple.run(runTime))
{
// pre-time-increment operations ...
runTime ++;
Info<< "Time = " << runTime.timeName() << nl << endl;
// solve ...
}
In constant/chemistryProperties in addition to the specification of the initial
ODE integration time-step used at the start of the run:
initialChemicalTimeStep 1e-12;
this time step may now also be specified for every chemistry integration by
setting the optional entry maxChemicalTimeStep, e.g.
maxChemicalTimeStep 1e-12;
