- kEpsilonPhitF is a kEpsilon-based model which originated
from (Durbin, 1995)’s v2-f methodology. However, the majority of
v2-f model variants proved to be numerically stiff for segregated
solution algorithms due to the coupled formulations of v2 and f fields,
particularly on wall boundaries.
The v2-f variant (i.e. OpenFOAM’s v2f model) due to
(Lien and Kalitzin, 2001) reformulated the original v2-f model to enable
segregated computations; however, a number of shortcomings regarding
the model fidelity were reported in the literature.
To overcome the shortcomings of the v2-f methodology, the v2-f approach
was re-evaluated by (Laurence et al., 2005) by transforming v2 scale into
its equivalent non-dimensional form, i.e. phit, to reduce the numerical
stiffness.
This variant, i.e. kEpsilonPhitF, is believed to provide numerical
robustness, and insensitivity to grid anomalies while retaining the
theoretical model fidelity of the original v2-f model.
Accordingly the v2f RANS model is deprecated in favour of the variant
kEpsilonPhitF model.
When activeDesignVariables are not set explicitly, all design variables
are treated as active. These were allocated properly when starting from
0 but not when starting from an intermediate optimisation cycle
(e.g. running 5 optimisation cycles, stopping and restarting).
TUT: added a new tutorial including the restart of an optimisation run
to help identify future regression
- The core of the FatalIOError message was not printed due to exiting
with FatalError instead of FatalIOError
- Changed the TypeName in all derived classes of displacementMethod so
that the toc printed by the FatalIOError corresponds to what the user
should add in dynamicMeshDict
When a contact resistance is used the T field on each coupled
patch is different due to the thermal resistance. Thus, instead
of solving for a unique Tw at the wall, we solve for Tw1 at one side
then, the Tnbr internal becomes Tw2, which is the T of the nbr
patch.
When a contact resistance is used the T field on each coupled
patch is different due to the thermal resistance. Thus, instead
of solving for a unique Tw at the wall, we solve for Tw1 at one side
then, the Tnbr internal becomes Tw2, which is the T of the nbr patch.
1) New skewCorrectedSnGrad for non-orthogonal and skewness corrector
2) New freeSurfacePressure and freeSurfacePressure working with
interfaceTrackingFvMesh
3) New interfaceTrackingFvMesh
- now use debug 2 for scanner and debug 4 for parser.
Provided better feedback about what is being parsed (debug mode)
- relocate debug application to applications/tools/foamExprParserInfo
See GL #1433
Applies corrections to turbulence kinetic energy equation and turbulence
viscosity field for incompressible multiphase flow cases.
Turbulence kinetic energy is over-predicted in VOF solvers at the phase
interface and throughout the water column in nearly-potential flow regions
beneath surface waves.
This fvOption applies corrections based on the references:
Buoyancy source term in turbulence kinetic energy equation:
Devolder, B., Rauwoens, P., and Troch, P. (2017).
Application of a buoyancy-modified k-w SST turbulence model to
simulate wave run-up around a monopile subjected to regular waves
using OpenFOAM.
Coastal Engineering, 125, 81-94.
Correction to turbulence viscosity field:
Larsen, B.E. and Fuhrman, D.R. (2018).
On the over-production of turbulence beneath surface waves in
Reynolds-averaged Navier-Stokes models
J. Fluid Mech, 853, 419-460
Example usage:
multiphaseStabilizedTurbulence1
{
type multiphaseStabilizedTurbulence;
active yes;
multiphaseStabilizedTurbulenceCoeffs
{
// Optional coefficients
lambda2 0.1; // A value of 0 sets the nut correction to 0
Cmu 0.09; // from k-epsilon model
C 1.51; // model coefficient from k-omega model
alpha 1.36; // 1/Prt
}
}
Thanks go to the Turbulence Technical Committee, and the useful discussions
with and code testing by Bjarke Eltard-Larsen and David Fuhrman (Technical
University of Denmark).
ENH: modify fWallFunction for kEpsilonPhitF model
The k-epsilon-phit-f turbulence closure model for incompressible and
compressible flows.
The model is a three-transport-equation linear-eddy-viscosity turbulence
closure model alongside an elliptic relaxation equation:
- Turbulent kinetic energy, \c k,
- Turbulent kinetic energy dissipation rate, \c epsilon,
- Normalised wall-normal fluctuating velocity scale, \c phit,
- Elliptic relaxation factor, \c f.
Reference:
\verbatim
Standard model (Tag:LUU):
Laurence, D. R., Uribe, J. C., & Utyuzhnikov, S. V. (2005).
A robust formulation of the v2−f model.
Flow, Turbulence and Combustion, 73(3-4), 169–185.
DOI:10.1007/s10494-005-1974-8
\endverbatim
The default model coefficients are (LUU:Eqs. 19-20):
\verbatim
kEpsilonPhitFCoeffs
{
Cmu 0.22, // Turbulent viscosity constant
Ceps1a 1.4, // Model constant for epsilon
Ceps1b 1.0, // Model constant for epsilon
Ceps1c 0.05, // Model constant for epsilon
Ceps2 1.9, // Model constant for epsilon
Cf1 1.4, // Model constant for f
Cf2 0.3, // Model constant for f
CL 0.25, // Model constant for L
Ceta 110.0, // Model constant for L
CT 6.0, // Model constant for T
sigmaK 1.0, // Turbulent Prandtl number for k
sigmaEps 1.3, // Turbulent Prandtl number for epsilon
sigmaPhit 1.0, // Turbulent Prandtl number for phit = sigmaK
}
\endverbatim
Note
The name of the original variable replacing 'v2' is 'phi' (LUU:Eq. 14).
However, the name 'phi' preexisted in OpenFOAM; therefore, this name was
replaced by 'phit'
qem and qin were not set to zero for the wideBand model BC.
qin was used in the grey model BC to calculate Ir(the total
incoming heat flux). As it is now set to zero, the grey model
loops over the incoming rays to calculate Ir instead of relaying
on qin stored in radiativeIntensityRay.
- follows the principle of least surprise if the expansion behaviour
for #eval and expressions (eg, exprFixedValue) are the same. This
is possible now that we harness the regular stringOps::expand()
within exprString::expand()
Adding check for p.active at the end of KinematicParcel::move.
p.hitFace() is called only for active parcels.
Setting to zero the initialization for stored lists of stick and
escape parcels
in LocalInteraction and StandardWallInteraction models
NOTE: KinematicParcel::hitPatch counts overall system escaped
parcels and mass based on polyPatch type and not on type of
patchInteractionModel. Thus, if a patch is a Wall for fluid
but escape for parcel the overall report will be wrong but
the local report for each patch is correct
