Select using the optional
consistent true;
setting in the PIMPLE dictionary of fvSolution.
This option is generally only beneficial for cases run in PIMPLE-mode
with a large maximum Courant number.
Select LTS via the ddtScheme:
ddtSchemes
{
default localEuler rDeltaT;
}
The LTS algorithm is currently controlled with the standard settings in
controlDict, e.g.:
maxCo 0.5;
maxDeltaT 2e-8;
with the addition of the optional rDeltaT smoothing coefficient:
rDeltaTSmoothingCoeff 0.02;
which defaults to 0.02.
ddtSchemes
{
default localEuler rDeltaT;
}
LTS is selected by the ddt scheme e.g. in the
tutorials/multiphase/interFoam/ras/DTCHull case:
ddtSchemes
{
default localEuler rDeltaT;
}
LTSInterFoam is no longer needed now that interFoam includes LTS
support.
//- Return the set of times selected based on the argList options
// including support for \b -newTimes in which times are selected
// if the file <fName> does not exist in the time directory.
// Also set the runTime to the first instance or the
// \c constant/ directory if no instances are specified or available
static instantList select
(
Time& runTime,
const argList& args,
const word& fName
);
This is experimental functionality and currently on test in the yPlus
post-processing utility.
With the SIMPLE "consistent" option and optimized relaxation factors
this tutorial now converges in 210 iterations, previously with SIMPLE it
took 950. Despite the increase in cost per time-step due to the
increase in relaxation factors and number of solver iterations the
speed-up is 3.5x.
to support laminar simulations in the new framework.
Unfortunately this allows LES models to be instantiated although they
are not compatible with steady-state simulations.
Select LTS via the ddtScheme:
ddtSchemes
{
default localEuler rDeltaT;
}
The LTS algorithm is controlled with the standard settings in
controlDict, e.g.:
maxCo 0.5;
maxDeltaT 2e-8;
with the addition of the optional rDeltaT smoothing coefficient:
rDeltaTSmoothingCoeff 0.02;
which defaults to 0.02.
For cases with reasonably uniform meshes like the forwardStep tutorial
LTS does not provide much benefit but for cases with large variation in
cell-size like the biconic25-55Run35 tutorial LTS provides significant
speed-up to convergence particularly if started from uniform conditions.
Reverted changes proposed in
http://openfoam.org/mantisbt/view.php?id=1548 as it adversely affects
fixed-value BCs and is formulated to fix an issue with an unphysical
case. Further analysis of the handling of fixed pressure outlet
conditions as the Mach number approaches 1 is required.
Use the trace as the limiter function for both symmTensor and tensor to
bound the normal stresses rather than the shear stresses.
Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1751
