diff --git a/src/combustionModels/Make/files b/src/combustionModels/Make/files
index 20de91ecc6..88e81afe8b 100644
--- a/src/combustionModels/Make/files
+++ b/src/combustionModels/Make/files
@@ -10,6 +10,7 @@ rhoCombustionModel/rhoCombustionModel/rhoCombustionModelNew.C
 rhoCombustionModel/rhoThermoCombustion/rhoThermoCombustion.C
 rhoCombustionModel/rhoChemistryCombustion/rhoChemistryCombustion.C
 
+diffusion/diffusions.C
 infinitelyFastChemistry/infinitelyFastChemistrys.C
 
 PaSR/PaSRs.C
diff --git a/src/combustionModels/diffusion/diffusion.C b/src/combustionModels/diffusion/diffusion.C
new file mode 100644
index 0000000000..b8cb1ed7ae
--- /dev/null
+++ b/src/combustionModels/diffusion/diffusion.C
@@ -0,0 +1,105 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "diffusion.H"
+#include "fvcGrad.H"
+
+namespace Foam
+{
+namespace combustionModels
+{
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+template<class CombThermoType, class ThermoType>
+diffusion<CombThermoType, ThermoType>::diffusion
+(
+    const word& modelType, const fvMesh& mesh
+)
+:
+    singleStepCombustion<CombThermoType, ThermoType>(modelType, mesh),
+    C_(readScalar(this->coeffs().lookup("C"))),
+    oxidantName_(this->coeffs().template lookupOrDefault<word>("oxidant", "O2"))
+{}
+
+
+// * * * * * * * * * * * * * * * * Destructors * * * * * * * * * * * * * * * //
+
+template<class CombThermoType, class ThermoType>
+diffusion<CombThermoType, ThermoType>::~diffusion()
+{}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+template<class CombThermoType, class ThermoType>
+void diffusion<CombThermoType, ThermoType>::correct()
+{
+    this->wFuel_ ==
+        dimensionedScalar("zero", dimMass/pow3(dimLength)/dimTime, 0.0);
+
+    if (this->active())
+    {
+        this->singleMixturePtr_->fresCorrect();
+
+        const label fuelI = this->singleMixturePtr_->fuelIndex();
+
+        const volScalarField& YFuel = this->thermoPtr_->composition().Y()[fuelI];
+
+        if (this->thermoPtr_->composition().contains(oxidantName_))
+        {
+            const volScalarField& YO2 =
+                this->thermoPtr_->composition().Y(oxidantName_);
+
+            this->wFuel_ ==
+                C_*this->turbulence().muEff()
+               *mag(fvc::grad(YFuel) & fvc::grad(YO2))
+               *pos(YFuel)*pos(YO2);
+        }
+    }
+}
+
+
+template<class CombThermoType, class ThermoType>
+bool diffusion<CombThermoType, ThermoType>::read()
+{
+    if (singleStepCombustion<CombThermoType, ThermoType>::read())
+    {
+        this->coeffs().lookup("C") >> C_ ;
+        this->coeffs().readIfPresent("oxidant", oxidantName_);
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace combustionModels
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
diff --git a/src/combustionModels/diffusion/diffusion.H b/src/combustionModels/diffusion/diffusion.H
new file mode 100644
index 0000000000..c3002a894f
--- /dev/null
+++ b/src/combustionModels/diffusion/diffusion.H
@@ -0,0 +1,122 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::combustionModels::diffusion
+
+Description
+    Simple diffusion-based combustion model based on the principle mixed is
+    burnt. Additional parameter C is used to distribute the heat release rate
+    in time.
+
+SourceFiles
+    diffusion.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef diffusion_H
+#define diffusion_H
+
+#include "singleStepCombustion.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace combustionModels
+{
+
+/*---------------------------------------------------------------------------*\
+                         Class diffusion Declaration
+\*---------------------------------------------------------------------------*/
+
+template<class CombThermoType, class ThermoType>
+class diffusion
+:
+    public singleStepCombustion<CombThermoType, ThermoType>
+{
+    // Private data
+
+        //- Model constant
+        scalar C_;
+
+        //- Name of oxidant - default is "O2"
+        word oxidantName_;
+
+
+    // Private Member Functions
+
+        //- Disallow copy construct
+        diffusion(const diffusion&);
+
+        //- Disallow default bitwise assignment
+        void operator=(const diffusion&);
+
+
+public:
+
+    //- Runtime type information
+    TypeName("diffusion");
+
+
+    // Constructors
+
+        //- Construct from components
+        diffusion(const word& modelType, const fvMesh& mesh);
+
+
+    //- Destructor
+    virtual ~diffusion();
+
+
+    // Member Functions
+
+        // Evolution
+
+            //- Correct combustion rate
+            virtual void correct();
+
+
+        // I-O
+
+            //- Update properties
+            virtual bool read();
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace combustionModels
+} // End namespace Foam
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+#   include "diffusion.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/combustionModels/diffusion/diffusions.C b/src/combustionModels/diffusion/diffusions.C
new file mode 100644
index 0000000000..73c201f0fc
--- /dev/null
+++ b/src/combustionModels/diffusion/diffusions.C
@@ -0,0 +1,74 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "makeCombustionTypes.H"
+
+#include "thermoPhysicsTypes.H"
+#include "psiThermoCombustion.H"
+#include "rhoThermoCombustion.H"
+#include "diffusion.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace combustionModels
+{
+    makeCombustionTypesThermo
+    (
+        diffusion,
+        psiThermoCombustion,
+        gasThermoPhysics,
+        psiCombustionModel
+    );
+
+    makeCombustionTypesThermo
+    (
+        diffusion,
+        psiThermoCombustion,
+        constGasThermoPhysics,
+        psiCombustionModel
+    );
+
+    makeCombustionTypesThermo
+    (
+        diffusion,
+        rhoThermoCombustion,
+        gasThermoPhysics,
+        rhoCombustionModel
+    );
+
+    makeCombustionTypesThermo
+    (
+        diffusion,
+        rhoThermoCombustion,
+        constGasThermoPhysics,
+        rhoCombustionModel
+    );
+}
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //