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added ability to specify beta for charge transfer reactions

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This commit is contained in:
Dave Goodwin 2004-09-20 10:18:02 +00:00
parent 9eb7ddb0e9
commit cfcb353a5f
5 changed files with 42 additions and 12 deletions
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38
Cantera/src/EdgeKinetics.cpp
View file

@ -42,7 +42,8 @@ namespace Cantera {
m_redo_rates(false),
m_nirrev(0),
m_nrev(0),
m_finalized(false)
m_finalized(false),
m_has_electrochem_rxns(false)
{
m_kdata = new EdgeKineticsData;
m_kdata->m_temp = 0.0;
@ -68,7 +69,8 @@ namespace Cantera {
if (T != m_kdata->m_temp || m_redo_rates) {
m_kdata->m_logtemp = log(T);
m_rates.update(T, m_kdata->m_logtemp, m_kdata->m_rfn.begin());
applyButlerVolmerCorrection(m_kdata->m_rfn.begin());
if (m_has_electrochem_rxns)
applyButlerVolmerCorrection(m_kdata->m_rfn.begin());
m_kdata->m_temp = T;
updateKc();
m_kdata->m_ROP_ok = false;
@ -220,7 +222,8 @@ namespace Cantera {
/**
* For reactions that transfer charge across a potential difference,
* the activation energies are modified by the potential difference.
* (see, for example, ...). This method applies this correction.
* (see, for example, Baird and Falkner, "Electrochemical Methods").
* This method applies this correction.
*/
void EdgeKinetics::applyButlerVolmerCorrection(doublereal* kf) {
int i;
@ -252,12 +255,16 @@ namespace Cantera {
// activation energy below zero.
doublereal ea, eamod;
for (i = 0; i < m_ii; i++) {
eamod = 0.5*m_rwork[i];
int nct = m_beta.size();
int irxn;
for (i = 0; i < nct; i++) {
irxn = m_ctrxn[i];
eamod = m_beta[i]*m_rwork[irxn];
//cout << "i, beta = " << i << " " << m_beta[i] << endl;
if (eamod != 0.0 && m_E[i] != 0.0) {
ea = GasConstant * m_E[i];
if (eamod + ea < 0.0) eamod = -ea;
kf[i] *= exp(-eamod*rrt);
kf[irxn] *= exp(-eamod*rrt);
}
}
}
@ -354,17 +361,28 @@ namespace Cantera {
void EdgeKinetics::
addElementaryReaction(const ReactionData& r) {
int iloc;
// install rate coeff calculator
vector_fp rp = r.rateCoeffParameters;
// coverage dependence
int ncov = r.cov.size();
for (int m = 0; m < ncov; m++) rp.push_back(r.cov[m]);
iloc = m_rates.install( reactionNumber(),
r.rateCoeffType, rp.size(),
iloc = m_rates.install( reactionNumber(), r.rateCoeffType, rp.size(),
rp.begin() );
// store activation energy
m_E.push_back(r.rateCoeffParameters[2]);
if (r.beta > 0.0) {
m_has_electrochem_rxns = true;
m_E.push_back(r.rateCoeffParameters[2]);
m_beta.push_back(r.beta);
m_ctrxn.push_back(reactionNumber());
}
// add constant term to rate coeff value vector
m_kdata->m_rfn.push_back(r.rateCoeffParameters[0]);
m_kdata->m_rfn.push_back(r.rateCoeffParameters[0]);
registerReaction( reactionNumber(), ELEMENTARY_RXN, iloc);
}

3
Cantera/src/EdgeKinetics.h
View file

@ -372,6 +372,8 @@ namespace Cantera {
vector_fp m_pot;
vector_fp m_rwork;
vector_fp m_E;
vector_fp m_beta;
vector_int m_ctrxn;
private:
@ -389,6 +391,7 @@ namespace Cantera {
}
void applyButlerVolmerCorrection(doublereal* kf);
bool m_finalized;
bool m_has_electrochem_rxns;
};
}

2
Cantera/src/ReactionData.h
View file

@ -34,6 +34,7 @@ namespace Cantera {
equation = "";
default_3b_eff = 1.0;
global = false;
beta = 0.0;
}
~ReactionData(){}
@ -58,6 +59,7 @@ namespace Cantera {
doublereal default_3b_eff;
vector_fp cov;
bool global;
doublereal beta; // for electrochemical reactions
};
}

8
Cantera/src/converters/ck2ct.cpp
View file

@ -388,10 +388,12 @@ namespace pip {
// two irreversible reactions.
if (r.reactions[i].krev.A != 0.0) {
addReaction(idktag, irxn,
cout << endl << "# [CK Reaction (+" << i+1 << ")]" << endl;
addReaction(idktag, irxn,
ckr::forwardReaction(r.reactions[i]), r.units, version);
irxn++;
addReaction(idktag, irxn,
cout << "# [CK Reaction (-" << (i+1) << ")]" << endl;
addReaction(idktag, irxn,
ckr::reverseReaction(r.reactions[i]), r.units, version);
irxn++;
}
@ -399,6 +401,8 @@ namespace pip {
// Otherwise, just add the whole reaction, which may or may
// not be reversible.
else {
if (i != irxn)
cout << endl << "# [CK Reaction (" << (i+1) << ")]" << endl;
addReaction(idktag, irxn, r.reactions[i],
r.units, version);
irxn++;

3
Cantera/src/importCTML.cpp
View file

@ -615,6 +615,9 @@ namespace Cantera {
else if (nm == "efficiencies") {
getEfficiencies(c, kin, rdata);
}
else if (nm == "electrochem") {
rdata.beta = fpValue(c["beta"]);
}
}
/*
* Store the coefficients in the ReactionData object for return