diff --git a/src/ThermophysicalTransportModels/laminar/laminarThermophysicalTransportModel/laminarThermophysicalTransportModel.H b/src/ThermophysicalTransportModels/laminar/laminarThermophysicalTransportModel/laminarThermophysicalTransportModel.H
index a9ce685ef9..715fbece6c 100644
--- a/src/ThermophysicalTransportModels/laminar/laminarThermophysicalTransportModel/laminarThermophysicalTransportModel.H
+++ b/src/ThermophysicalTransportModels/laminar/laminarThermophysicalTransportModel/laminarThermophysicalTransportModel.H
@@ -181,6 +181,27 @@ public:
             return this->thermo().alphahe(patchi);
         }
 
+        //- Effective mass diffusivity for a given specie mass-fraction [kg/m/s]
+        virtual tmp<volScalarField> DEff(const volScalarField& Yi) const
+        {
+            return volScalarField::New
+            (
+                "DEff",
+                alphaEff()
+            );
+        }
+
+        //- Effective mass diffusivity for a given specie mass-fraction
+        //  for patch [kg/m/s]
+        virtual tmp<scalarField> DEff
+        (
+            const volScalarField& Yi,
+            const label patchi
+        ) const
+        {
+            return alphaEff(patchi);
+        }
+
         //- Correct the laminar transport
         virtual void correct();
 
diff --git a/src/ThermophysicalTransportModels/thermophysicalTransportModel/thermophysicalTransportModel.H b/src/ThermophysicalTransportModels/thermophysicalTransportModel/thermophysicalTransportModel.H
index 266aa3bd3a..e7fd06c587 100644
--- a/src/ThermophysicalTransportModels/thermophysicalTransportModel/thermophysicalTransportModel.H
+++ b/src/ThermophysicalTransportModels/thermophysicalTransportModel/thermophysicalTransportModel.H
@@ -116,6 +116,17 @@ public:
         //  for patch [kg/m/s]
         virtual tmp<scalarField> alphaEff(const label patchi) const = 0;
 
+        //- Effective mass diffusivity for a given specie mass-fraction [kg/m/s]
+        virtual tmp<volScalarField> DEff(const volScalarField& Yi) const = 0;
+
+        //- Effective mass diffusivity for a given specie mass-fraction
+        //  for patch [kg/m/s]
+        virtual tmp<scalarField> DEff
+        (
+            const volScalarField& Yi,
+            const label patchi
+        ) const = 0;
+
         //- Return the heat flux
         virtual tmp<volVectorField> q() const = 0;
 
diff --git a/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.C b/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.C
index 0e6dcdb460..3eeb5beaf4 100644
--- a/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.C
+++ b/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.C
@@ -175,7 +175,7 @@ eddyDiffusivity<TurbulenceThermophysicalTransportModel>::j
             "j(" + Yi.name() + ')',
             this->momentumTransport().alphaRhoPhi().group()
         ),
-       -this->alphaEff()*this->alpha()*fvc::grad(Yi)
+       -this->DEff(Yi)*this->alpha()*fvc::grad(Yi)
     );
 }
 
@@ -187,7 +187,7 @@ eddyDiffusivity<TurbulenceThermophysicalTransportModel>::divj
     volScalarField& Yi
 ) const
 {
-    return -fvm::laplacian(this->alpha()*this->alphaEff(), Yi);
+    return -fvm::laplacian(this->alpha()*this->DEff(Yi), Yi);
 }
 
 
diff --git a/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.H b/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.H
index 25d7b527a7..c7c84a9c00 100644
--- a/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.H
+++ b/src/ThermophysicalTransportModels/turbulence/eddyDiffusivity/eddyDiffusivity.H
@@ -178,6 +178,27 @@ public:
             );
         }
 
+        //- Effective mass diffusivity for a given specie mass-fraction [kg/m/s]
+        virtual tmp<volScalarField> DEff(const volScalarField& Yi) const
+        {
+            return volScalarField::New
+            (
+                "DEff",
+                alphaEff()
+            );
+        }
+
+        //- Effective mass diffusivity for a given specie mass-fraction
+        //  for patch [kg/m/s]
+        virtual tmp<scalarField> DEff
+        (
+            const volScalarField& Yi,
+            const label patchi
+        ) const
+        {
+            return alphaEff(patchi);
+        }
+
         //- Return the heat flux
         virtual tmp<volVectorField> q() const;
 
diff --git a/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.C b/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.C
index 6a67735993..37c2482e07 100644
--- a/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.C
+++ b/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.C
@@ -95,17 +95,17 @@ nonUnityLewisEddyDiffusivity<TurbulenceThermophysicalTransportModel>::q() const
 
         const PtrList<volScalarField>& Y = composition.Y();
 
-        volScalarField alphaEffMinusDEff
+        volScalarField alphatMinusDt
         (
-            "alphaEffMinusDEff",
-            this->alphaEff()*(1 - this->Prt_/Sct_)
+            "alphatMinusDt",
+            this->alphat()*(1 - this->Prt_/Sct_)
         );
 
         forAll(Y, i)
         {
             tmpq.ref() +=
                 this->alpha()
-               *alphaEffMinusDEff
+               *alphatMinusDt
                *composition.HE(i, this->thermo().p(), this->thermo().T())
                *fvc::grad(Y[i]);
         }
@@ -131,10 +131,10 @@ nonUnityLewisEddyDiffusivity<TurbulenceThermophysicalTransportModel>::divq
 
         const PtrList<volScalarField>& Y = composition.Y();
 
-        volScalarField alphaEffMinusDEff
+        volScalarField alphatMinusDt
         (
-            "alphaEffMinusDEff",
-            this->alphaEff()*(1 - this->Prt_/Sct_)
+            "alphatMinusDt",
+            this->alphat()*(1 - this->Prt_/Sct_)
         );
 
         forAll(Y, i)
@@ -143,7 +143,7 @@ nonUnityLewisEddyDiffusivity<TurbulenceThermophysicalTransportModel>::divq
                 fvc::laplacian
                 (
                     this->alpha()
-                   *alphaEffMinusDEff
+                   *alphatMinusDt
                    *composition.HE(i, this->thermo().p(), this->thermo().T()),
                     Y[i]
                 );
@@ -154,32 +154,6 @@ nonUnityLewisEddyDiffusivity<TurbulenceThermophysicalTransportModel>::divq
 }
 
 
-template<class TurbulenceThermophysicalTransportModel>
-tmp<volVectorField>
-nonUnityLewisEddyDiffusivity<TurbulenceThermophysicalTransportModel>::j
-(
-    const volScalarField& Yi
-) const
-{
-    return
-        this->Prt_/Sct_
-       *eddyDiffusivity<TurbulenceThermophysicalTransportModel>::j(Yi);
-}
-
-
-template<class TurbulenceThermophysicalTransportModel>
-tmp<fvScalarMatrix>
-nonUnityLewisEddyDiffusivity<TurbulenceThermophysicalTransportModel>::divj
-(
-    volScalarField& Yi
-) const
-{
-    return
-        this->Prt_/Sct_
-       *eddyDiffusivity<TurbulenceThermophysicalTransportModel>::divj(Yi);
-}
-
-
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace turbulenceThermophysicalTransportModels
diff --git a/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.H b/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.H
index 91cc9292aa..21c2b21a30 100644
--- a/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.H
+++ b/src/ThermophysicalTransportModels/turbulence/nonUnityLewisEddyDiffusivity/nonUnityLewisEddyDiffusivity.H
@@ -27,7 +27,8 @@ Class
 Description
     Non-unity-Lewis-Eddy-diffusivity based gradient heat flux model for RAS or
     LES of turbulent flow. Allows independent specification of turbulent
-    Prandtl and Schmidt numbers.
+    Prandtl and Schmidt numbers. The laminar Lewis number is still assumed to
+    equal one.
 
 Usage
     \verbatim
@@ -113,17 +114,36 @@ public:
         //- Read thermophysicalTransport dictionary
         virtual bool read();
 
+        //- Effective mass diffusivity for a given specie mass-fraction [kg/m/s]
+        virtual tmp<volScalarField> DEff(const volScalarField& Yi) const
+        {
+            return volScalarField::New
+            (
+                "DEff",
+                this->thermo().alphaEff(this->Prt_/Sct_*this->alphat())
+            );
+        }
+
+        //- Effective mass diffusivity for a given specie mass-fraction
+        //  for patch [kg/m/s]
+        virtual tmp<scalarField> DEff
+        (
+            const volScalarField& Yi,
+            const label patchi
+        ) const
+        {
+            return this->thermo().alphaEff
+            (
+                this->Prt_.value()/Sct_.value()*this->alphat(patchi),
+                patchi
+            );
+        }
+
         //- Return the heat flux
         virtual tmp<volVectorField> q() const;
 
         //- Return the source term for the energy equation
         virtual tmp<fvScalarMatrix> divq(volScalarField& he) const;
-
-        //- Return the specie flux for the given specie mass-fraction
-        virtual tmp<volVectorField> j(const volScalarField& Yi) const;
-
-        //- Return the source term for the given specie mass-fraction equation
-        virtual tmp<fvScalarMatrix> divj(volScalarField& Yi) const;
 };