When an fvModel source introduces fluid into a simulation it should also
create a corresponding source term for all properties transported into
the domain by that injection. The source is, effectively, an alternative
form of inlet boundary, on which all transported properties need an
inlet value specified.
These values are now specified in the property field files. The
following is an example of a 0/U file in which the velocity of fluid
introduced by a fvModel source called "injection1" is set to a fixed
value of (-1 0 0):
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
#includeEtc "caseDicts/setConstraintTypes"
wall
{
type noSlip;
}
atmosphere
{
type pressureInletOutletVelocity;
value $internalField;
}
}
// *** NEW ***
sources
{
injection1
{
type uniformFixedValue;
uniformValue (-1 0 0);
}
}
And the following entry in the 0/k file specifies the turbulent kinetic
energy introduced as a fraction of the mean flow kinetic energy:
sources
{
injection1
{
type turbulentIntensityKineticEnergy;
intensity 0.05;
}
}
The specification is directly analogous to boundary conditions. The
conditions are run-time selectable and can be concisely implemented.
They can access each other and be inter-dependent (e.g., the above,
where turbulent kinetic energy depends on velocity). The syntax keeps
field data localised and makes the source model (e.g., massSource,
volumeSource, ...) specification independent from what other models and
fields are present in the simulation. The 'fieldValues' entry previously
required by source models is now no longer required.
If source values need specifying and no source condition has been
supplied in the relevant field file then an error will be generated.
This error is similar to that generated for missing boundary conditions.
This replaces the behaviour where sources such as these would introduce
a value of zero, either silently or with a warning. This is now
considered unacceptable. Zero might be a tolerable default for certain
fields (U, k), but is wholly inappropriate for others (T, epsilon, rho).
This change additionally makes it possible to inject fluid into a
multicomponent solver with a specified temperature. Previously, it was
not possible to do this as there was no means of evaluating the energy
of fluid with the injected composition.
for thermophysical transport within stationary solid phases. This provides a
consistent interface to heat transport within solids for single and now
multiphase solvers so that for example the wallHeatFlux functionObject can now
be used with multiphaseEuler, see tutorials/multiphaseEuler/boilingBed.
Also this development supports anisotropic thermal conductivity within the
stationary solid regions which was not possible previously.
The tutorials/multiphaseEuler/bed and tutorials/multiphaseEuler/boilingBed
tutorial cases have been updated for phaseSolidThermophysicalTransportModel by
changing the thermo type in physicalProperties.solid to heSolidThermo. This
change will need to be made to all multiphaseEuler cases involving stationary
phases.
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.
