This change makes multiphaseEuler more consistent with other modules and
makes its sub-libraries less inter-dependent. Some left-over references
to multiphaseEulerFoam have also been removed.
The momentum equation central coefficient and drag matrix is formulated,
inverted and used to eliminate the drag terms from each of the phase momentum
equations which are combined for formulate a drag-implicit pressure equation.
This eliminates the lagged drag terms from the previous formulation which
significantly improves convergence for small particle and Euler-VoF high-drag
cases.
It would also be possible to refactor the virtual-mass terms and include the
central coefficients of the phase acceleration terms in the drag matrix before
inversion to further improve the implicitness of the phase momentum-pressure
coupling for bubbly flows. This work is pending funding.
for the multiphaseEuler solver module, replacing the more specific
uniformFixedMultiphaseHeatFluxFvPatchScalarField as it provide equivalent
functionality if the heat-flux q is specified.
multiphaseExternalTemperatureFvPatchScalarField is derived from the refactored
and generalised externalTemperatureFvPatchScalarField, overriding the
getKappa member function to provide the multiphase equivalents of kappa and
other heat transfer properties. All controls for
multiphaseExternalTemperatureFvPatchScalarField are the same as for
externalTemperatureFvPatchScalarField:
Class
Foam::externalTemperatureFvPatchScalarField
Description
This boundary condition applies a heat flux condition to temperature
on an external wall. Heat flux can be specified in the following ways:
- Fixed power: requires \c Q
- Fixed heat flux: requires \c q
- Fixed heat transfer coefficient: requires \c h and \c Ta
where:
\vartable
Q | Power Function1 of time [W]
q | Heat flux Function1 of time [W/m^2]
h | Heat transfer coefficient Function1 of time [W/m^2/K]
Ta | Ambient temperature Function1 of time [K]
\endvartable
Only one of \c Q or \c q may be specified, if \c h and \c Ta are also
specified the corresponding heat-flux is added.
If the heat transfer coefficient \c h is specified an optional thin thermal
layer resistances can also be specified through thicknessLayers and
kappaLayers entries.
The patch thermal conductivity \c kappa is obtained from the region
thermophysicalTransportModel so that this boundary condition can be applied
directly to either fluid or solid regions.
Usage
\table
Property | Description | Required | Default value
Q | Power [W] | no |
q | Heat flux [W/m^2] | no |
h | Heat transfer coefficient [W/m^2/K] | no |
Ta | Ambient temperature [K] | if h is given |
thicknessLayers | Layer thicknesses [m] | no |
kappaLayers | Layer thermal conductivities [W/m/K] | no |
relaxation | Relaxation for the wall temperature | no | 1
emissivity | Surface emissivity for radiative flux to ambient | no | 0
qr | Name of the radiative field | no | none
qrRelaxation | Relaxation factor for radiative field | no | 1
\endtable
Example of the boundary condition specification:
\verbatim
<patchName>
{
type externalTemperature;
Ta constant 300.0;
h uniform 10.0;
thicknessLayers (0.1 0.2 0.3 0.4);
kappaLayers (1 2 3 4);
value $internalField;
}
\endverbatim
See also
Foam::mixedFvPatchScalarField
Foam::Function1
If the libs entry is not provided and the name of the library containing the
functionObject, fvModel or fvConstraint corresponds to the type specified the
corresponding library is automatically loaded, e.g. to apply the
VoFTurbulenceDamping fvModel to an incompressibleVoF simulation the following
will load the libVoFTurbulenceDamping.so library automatically and instantiate
the fvModel:
turbulenceDamping
{
type VoFTurbulenceDamping;
delta 1e-4;
}
