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Generalization of the getStick() routine, to include the

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case where you have bulk reactants as well as surface reactants
and a single gas phase reactant.
This commit is contained in:
Harry Moffat 2005-10-22 00:53:22 +00:00
parent df149f7f6c
commit 2fe5f76650
1 changed files with 50 additions and 13 deletions
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63
Cantera/src/importCTML.cpp
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@ -466,8 +466,21 @@ namespace Cantera {
}
/**
* getStick() processes the element called Stick that specifies
* sticking coefficients.
* getStick() processes the XML element called Stick that specifies
* the sticking coefficient reaction. This routine will
* translate the sticking coefficient value into a "normal"
* rate constant for the surface reaction.
*
* Output
* -----------
* Output is the normal Arrhenius expressions for a surface
* reaction rate constant.
*
* A - units such that rate of rxn has kmol/m^2/s when
* A is multiplied by activity concentrations of
* reactants in the normal manner.
* n - unitless
* E - Units 1/Kelvin
*/
static void getStick(const XML_Node& node, Kinetics& kin,
ReactionData& r, doublereal& A, doublereal& b, doublereal& E) {
@ -476,11 +489,21 @@ namespace Cantera {
int np = 0;
doublereal f = 1.0;
doublereal order;
/*
* species is the name of the special reactant whose surface
* flux rate will be calculated.
* isp = species # in the local phase
* ispKinetics = species # in the kinetics object
* ispPhaseIndex = phase # of the special species
*/
string spname = node["species"];
ThermoPhase& th = kin.speciesPhase(spname);
int isp = th.speciesIndex(spname);
double mw = th.molecularWeights()[isp];
int isp = th.speciesIndex(spname);
int ispKinetics = kin.kineticsSpeciesIndex(spname);
int ispPhaseIndex = kin.speciesPhaseIndex(ispKinetics);
double ispMW = th.molecularWeights()[isp];
double sc;
// loop over the reactants
for (int n = 0; n < nr; n++) {
@ -488,8 +511,8 @@ namespace Cantera {
order = r.order[n]; // stoich coeff
// get the phase species k belongs to
np = kin.speciesPhaseIndex(k);
const ThermoPhase& p = kin.thermo(np);
np = kin.speciesPhaseIndex(k);
const ThermoPhase& p = kin.thermo(np);
// get the local index of species k in this phase
klocal = p.speciesIndex(kin.kineticsSpeciesName(k));
@ -500,19 +523,33 @@ namespace Cantera {
// to coverages used in the sticking probability
// expression
if (p.eosType() == cSurf || p.eosType() == cEdge) {
f /= pow(p.standardConcentration(klocal), order);
sc = p.standardConcentration(klocal);
f /= pow(sc, order);
}
// otherwise, increment the counter of bulk species
else
not_surf++;
// Otherwise:
else {
// We only allow one species to be in the phase
// containing the special sticking coefficient
// species.
if (ispPhaseIndex == np) {
not_surf++;
}
// Other bulk phase species on the other side
// of ther interface are treated like surface
// species.
else {
sc = p.standardConcentration(klocal);
f /= pow(sc, order);
}
}
}
if (not_surf != 1) {
throw CanteraError("getStick",
"reaction probabilities can only be used in "
"reactions with exactly 1 bulk species.");
"reactions with exactly 1 gas/liquid species.");
}
doublereal cbar = sqrt(8.0*GasConstant/(Pi*mw));
doublereal cbar = sqrt(8.0*GasConstant/(Pi*ispMW));
A = 0.25 * getFloat(node, "A", "-") * cbar * f;
b = getFloat(node, "b") + 0.5;
E = getFloat(node, "E", "actEnergy");