An adsorption condition has been added for species mass fraction. This
models a surface on which one or more species deposit at a rate
proportional to the quantity of that specie present. The property that
the rate is assumed proportional to can be chosen to be mass fraction,
mole fraction, molar concentration, or partial pressure.
Example specification in 0/CH4, 0/O2, etc...:
<patchName>
{
type adsorptionMassFraction;
property molarConcentration;
c 1e-3; // <-- Transfer coefficient
value $internalField;
}
"c" is the constant of proportionality between the property value and
the mass transfer rate. If a specie does not adsorb, this should be set
to zero, or be omitted entirely.
This condition must be supplied for all species, and corresponding
specie transfer boundary conditions must also be applied to velocity and
temperature.
Example specification in 0/U and 0/T:
<patchName>
{
type specieTransferVelocity;
value $internalField;
}
<patchName>
{
type specieTransferTemperature;
value $internalField;
}
In addition, the semi-permeable baffle conditions have been refactored
to share functionality with the new adsorption conditions. They can now
also be used with the species-transfer temperature condition, which
corrects an energy error that was present previously. The parameter
"input" has been renamed "property", consistently with the adsorption
entries listed above. Molar concentration has also been added as an
option for the property driving the transfer, so the available controls
are the same as for adsorption.
Example specification in 0/CH4, 0/O2, etc...:
<patchName>
{
type semiPermeableBaffleMassFraction;
samplePatch <neighbourPatchName>;
property molarConcentration;
c 1e-3; // <-- Transfer coefficient
value $internalField;
}
<neighbourPatchName>
{
type semiPermeableBaffleMassFraction;
samplePatch <patchName>;
property molarConcentration;
c 1e-3; // <-- Transfer coefficient
value $internalField;
}
Velocity and temperature conditions should be set in the same way as for
adsorption.
In order for the temperature condition to function satisfactorily and
not introduce unphysical variations in temperature as a result of the
linearisation to an energy boundary condition, two new base classes for
temperature conditions which explicitly set the parameters of either
gradient or mixed energy conditions have been added. The mixed condition
forms the base of the specieTransferTemperature condition.
As a result of its generalisation, the library has been renamed from
"libsemiPermeableBaffle.so" to "libspecieTransfer.so".
bcc86701bc