LangmuirHinshelwoodReactionRate: corrected, rationalized and generalized

to an arbitrary pair of reacting species.

Description
    Langmuir-Hinshelwood reaction rate for gaseous reactions on surfaces.

    Reference:
    \verbatim
        Hinshelwood, C.N. (1940).
        The Kinetics of Chemical Change.
        Oxford Clarendon Press
    \endverbatim

src/thermophysicalModels/specie/reaction/reactionRate/LangmuirHinshelwood/LangmuirHinshelwoodReactionRate.H

@@ -25,7 +25,14 @@ Class
     Foam::LangmuirHinshelwoodReactionRate
 
 Description
-    Power series reaction rate.
+    Langmuir-Hinshelwood reaction rate for gaseous reactions on surfaces.
+
+    Reference:
+    \verbatim
+        Hinshelwood, C.N. (1940).
+        The Kinetics of Chemical Change.
+        Oxford Clarendon Press
+    \endverbatim
 
 SourceFiles
     LangmuirHinshelwoodReactionRateI.H
@@ -58,29 +65,24 @@ class LangmuirHinshelwoodReactionRate
 {
     // Private data
 
-        static const label n_ = 5;
+        //- List of species present in reaction system
+        const speciesTable& species_;
+
+        static const label n_ = 3;
         scalar A_[n_];
         scalar Ta_[n_];
 
-        label co_;
-        label c3h6_;
-        label no_;
+        //- Index of specie "A"
+        label a_;
+
+        //- Index of specie "B"
+        label b_;
 
 
 public:
 
     // Constructors
 
-        //- Construct from components
-        inline LangmuirHinshelwoodReactionRate
-        (
-            const scalar A[],
-            const scalar Ta[],
-            const label co,
-            const label c3h6,
-            const label no
-        );
-
         //- Construct from dictionary
         inline LangmuirHinshelwoodReactionRate
         (

src/thermophysicalModels/specie/reaction/reactionRate/LangmuirHinshelwood/LangmuirHinshelwoodReactionRateI.H

@@ -28,38 +28,17 @@ License
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-inline Foam::LangmuirHinshelwoodReactionRate::LangmuirHinshelwoodReactionRate
-(
-    const scalar A[],
-    const scalar Ta[],
-    const label co,
-    const label c3h6,
-    const label no
-)
-:
-    co_(co),
-    c3h6_(c3h6),
-    no_(no)
-{
-    for (int i=0; i<n_; i++)
-    {
-        A_[i] = A[i];
-        Ta_[i] = Ta[i];
-    }
-}
-
-
 inline Foam::LangmuirHinshelwoodReactionRate::LangmuirHinshelwoodReactionRate
 (
     const speciesTable& st,
     const dictionary& dict
 )
 :
-    co_(st["CO"]),
-    c3h6_(st["C3H6"]),
-    no_(st["NO"])
+    species_(st),
+    a_(st["A"]),
+    b_(st["B"])
 {
-    // read (A, Ta) pairs
+    // Read (A, Ta) pairs
     FixedList<Tuple2<scalar, scalar>, n_> coeffs(dict.lookup("coeffs"));
 
     forAll(coeffs, i)
@@ -81,10 +60,7 @@ inline Foam::scalar Foam::LangmuirHinshelwoodReactionRate::operator()
 {
     return A_[0]*exp(-Ta_[0]/T)/
     (
-        T
-       *sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[co_] + A_[2]*exp(-Ta_[2]/T)*c[c3h6_])
-       *(1 + A_[3]*exp(-Ta_[3]/T)*sqr(c[co_])*sqr(c[c3h6_]))
-       *(1 + A_[4]*exp(-Ta_[4]/T)*pow(c[no_], 0.7))
+        T*sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[a_] + A_[2]*exp(-Ta_[2]/T)*c[b_])
     );
 }
 
@@ -96,36 +72,20 @@ inline Foam::scalar Foam::LangmuirHinshelwoodReactionRate::ddT
     const scalarField& c
 ) const
 {
-    scalar den =
+    const scalar den =
     (
-        T
-       *sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[co_] + A_[2]*exp(-Ta_[2]/T)*c[c3h6_])
-       *(1 + A_[3]*exp(-Ta_[3]/T)*sqr(c[co_])*sqr(c[c3h6_]))
-       *(1 + A_[4]*exp(-Ta_[4]/T)*pow(c[no_], 0.7))
+        T*sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[a_] + A_[2]*exp(-Ta_[2]/T)*c[b_])
     );
-    scalar rate = A_[0]*exp(-Ta_[0]/T)/ den;
+    const scalar rate = A_[0]*exp(-Ta_[0]/T)/den;
 
-    scalar derivDen =
+    const scalar derivDen =
     (
-        sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[co_] + A_[2]*exp(-Ta_[2]/T)*c[c3h6_])
-       *(1 + A_[3]*exp(-Ta_[3]/T)*sqr(c[co_])*sqr(c[c3h6_]))
-       *(1 + A_[4]*exp(-Ta_[4]/T)*pow(c[no_], 0.7))
-      + 2*T*(1 + A_[1]*exp(-Ta_[1]/T)*c[co_] + A_[2]*exp(-Ta_[2]/T)*c[c3h6_])
-       *
-        (
-            A_[1]*exp(-Ta_[1]/T)*c[co_]*Ta_[1]/sqr(T)
-          + A_[2]*exp(-Ta_[2]/T)*c[c3h6_]*Ta_[2]/sqr(T)
+        sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[a_] + A_[2]*exp(-Ta_[2]/T)*c[b_])
+      + 2*T*(1 + A_[1]*exp(-Ta_[1]/T)*c[a_] + A_[2]*exp(-Ta_[2]/T)*c[b_])
+       *(
+            A_[1]*exp(-Ta_[1]/T)*c[a_]*Ta_[1]/sqr(T)
+          + A_[2]*exp(-Ta_[2]/T)*c[b_]*Ta_[2]/sqr(T)
         )
-       *(1 + A_[3]*exp(-Ta_[3]/T)*sqr(c[co_])*sqr(c[c3h6_]))
-       *(1 + A_[4]*exp(-Ta_[4]/T)*pow(c[no_], 0.7))
-      + T
-       *sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[co_] + A_[2]*exp(-Ta_[2]/T)*c[c3h6_])
-       *(A_[3]*exp(-Ta_[3]/T)*Ta_[3]*sqr(c[co_])*sqr(c[c3h6_])/sqr(T))
-       *(1 + A_[4]*exp(-Ta_[4]/T)*pow(c[no_], 0.7))
-      + T
-       *sqr(1 + A_[1]*exp(-Ta_[1]/T)*c[co_] + A_[2]*exp(-Ta_[2]/T)*c[c3h6_])
-       *(1 + A_[3]*exp(-Ta_[3]/T)*sqr(c[co_])*sqr(c[c3h6_]))
-       *(A_[4]*exp(-Ta_[4]/T)*Ta_[4]*pow(c[no_], 0.7))/sqr(T)
     );
 
     return rate*(Ta_[0]/sqr(T) - derivDen/den);
@@ -162,6 +122,9 @@ inline Foam::scalar Foam::LangmuirHinshelwoodReactionRate::dcidT
 
 inline void Foam::LangmuirHinshelwoodReactionRate::write(Ostream& os) const
 {
+    os.writeKeyword("A") << species_[a_] << token::END_STATEMENT << nl;
+    os.writeKeyword("B") << species_[b_] << token::END_STATEMENT << nl;
+
     FixedList<Tuple2<scalar, scalar>, n_> coeffs;
 
     forAll(coeffs, i)

src/thermophysicalModels/specie/reaction/reactionRate/MichaelisMenten/MichaelisMentenReactionRate.H

@@ -64,7 +64,7 @@ class MichaelisMentenReactionRate
 {
     // Private data
 
-        //- List of specie names present in reaction system
+        //- List of species present in reaction system
         const speciesTable& species_;
 
         //- The maximum reaction rate at saturating substrate concentration