From 4a810cbe9d3b3501552cce4b89881362c9664640 Mon Sep 17 00:00:00 2001
From: Henry Weller <http://openfoam.org>
Date: Tue, 23 Jul 2019 11:48:14 +0100
Subject: [PATCH] SpalartAllmaras[I][D]DES: Named temporary fields and added
 optional caching for LESRegion

The various temporary fields used to create the nuTilda equation sources are now
internal fields to avoid unnecessary evaluation of boundary conditions, lowering
storage and reducing CPU time, particularly when running in parallel.  These
temporary fields are now named with respect to the model so that they can be
cached conveniently and written as required.

The LESRegion field can now be contructed on demand if it is requested as a
cached temporary field and written out for diagnostics if needed, for example in
the tutorials/incompressible/pisoFoam/LES/motorBike tutorial:

cacheTemporaryObjects
(
    SpalartAllmarasDDES:LESRegion
);

functions
{
    writeCachedObjects
    {
        type        writeObjects;
        libs        ("libutilityFunctionObjects.so");

        writeControl writeTime;
        writeOption anyWrite;

        objects
        (
            SpalartAllmarasDDES:LESRegion
        );
    }

    #include "cuttingPlane"
    #include "streamLines"
    #include "forceCoeffs"
}
---
 .../SpalartAllmarasDDES/SpalartAllmarasDDES.C |  54 +++--
 .../SpalartAllmarasDDES/SpalartAllmarasDDES.H |  18 +-
 .../SpalartAllmarasDES/SpalartAllmarasDES.C   | 191 ++++++++++--------
 .../SpalartAllmarasDES/SpalartAllmarasDES.H   |  56 ++---
 .../SpalartAllmarasIDDES.C                    | 112 ++++++----
 .../SpalartAllmarasIDDES.H                    |  33 ++-
 .../LES/motorBike/lesFiles/controlDict        |  19 ++
 7 files changed, 286 insertions(+), 197 deletions(-)

diff --git a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.C b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.C
index 3f35ffbbaf..b32de5347d 100644
--- a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.C
+++ b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.C
@@ -35,44 +35,38 @@ namespace LESModels
 // * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDDES<BasicTurbulenceModel>::rd
+tmp<volScalarField::Internal> SpalartAllmarasDDES<BasicTurbulenceModel>::rd
 (
-    const volScalarField& magGradU
+    const volScalarField::Internal& magGradU
 ) const
 {
-    tmp<volScalarField> tr
+    return volScalarField::Internal::New
     (
-        volScalarField::New
+        modelName("rd"),
+        min
         (
-            modelName("rd"),
-            min
-            (
-                this->nuEff()
-               /(
-                   max
-                   (
-                       magGradU,
-                       dimensionedScalar(magGradU.dimensions(), small)
-                   )
-                  *sqr(this->kappa_*this->y_)
-               ),
-                scalar(10)
-            )
+            this->nuEff()()
+           /(
+                max
+                (
+                    magGradU,
+                    dimensionedScalar(magGradU.dimensions(), small)
+                )
+               *sqr(this->kappa_*this->y_())
+            ),
+            scalar(10)
         )
     );
-    tr.ref().boundaryFieldRef() == 0.0;
-
-    return tr;
 }
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDDES<BasicTurbulenceModel>::fd
+tmp<volScalarField::Internal> SpalartAllmarasDDES<BasicTurbulenceModel>::fd
 (
-    const volScalarField& magGradU
+    const volScalarField::Internal& magGradU
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("fd"),
         1 - tanh(pow3(8*rd(magGradU)))
@@ -83,14 +77,14 @@ tmp<volScalarField> SpalartAllmarasDDES<BasicTurbulenceModel>::fd
 // * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDDES<BasicTurbulenceModel>::dTilda
+tmp<volScalarField::Internal> SpalartAllmarasDDES<BasicTurbulenceModel>::dTilda
 (
-    const volScalarField& chi,
-    const volScalarField& fv1,
-    const volTensorField& gradU
+    const volScalarField::Internal& chi,
+    const volScalarField::Internal& fv1,
+    const volTensorField::Internal& gradU
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("dTilda"),
         max
@@ -99,7 +93,7 @@ tmp<volScalarField> SpalartAllmarasDDES<BasicTurbulenceModel>::dTilda
           - fd(mag(gradU))
            *max
             (
-                this->y_ - this->CDES_*this->delta(),
+                this->y_() - this->CDES_*this->delta()(),
                 dimensionedScalar(dimLength, 0)
             ),
             dimensionedScalar(dimLength, small)
diff --git a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.H b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.H
index d04a6c0dd8..18b98d44a9 100644
--- a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.H
+++ b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDDES/SpalartAllmarasDDES.H
@@ -65,9 +65,15 @@ class SpalartAllmarasDDES
 {
     // Private Member Functions
 
-        tmp<volScalarField> fd(const volScalarField& magGradU) const;
+        tmp<volScalarField::Internal> fd
+        (
+            const volScalarField::Internal& magGradU
+        ) const;
 
-        tmp<volScalarField> rd(const volScalarField& magGradU) const;
+        tmp<volScalarField::Internal> rd
+        (
+            const volScalarField::Internal& magGradU
+        ) const;
 
 
 protected:
@@ -77,11 +83,11 @@ protected:
         using IOobject::modelName;
 
         //- Length scale
-        virtual tmp<volScalarField> dTilda
+        virtual tmp<volScalarField::Internal> dTilda
         (
-            const volScalarField& chi,
-            const volScalarField& fv1,
-            const volTensorField& gradU
+            const volScalarField::Internal& chi,
+            const volScalarField::Internal& fv1,
+            const volTensorField::Internal& gradU
         ) const;
 
 
diff --git a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.C b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.C
index dd132b5e65..5b901d1575 100644
--- a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.C
+++ b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.C
@@ -40,7 +40,8 @@ tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::chi() const
 {
     return volScalarField::New
     (
-        modelName("chi"), nuTilda_/this->nu()
+        modelName("chi"),
+        nuTilda_/this->nu()
     );
 }
 
@@ -61,13 +62,13 @@ tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::fv1
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::fv2
+tmp<volScalarField::Internal> SpalartAllmarasDES<BasicTurbulenceModel>::fv2
 (
-    const volScalarField& chi,
-    const volScalarField& fv1
+    const volScalarField::Internal& chi,
+    const volScalarField::Internal& fv1
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("fv2"),
         1.0 - chi/(1.0 + chi*fv1)
@@ -76,26 +77,12 @@ tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::fv2
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::S
+tmp<volScalarField::Internal> SpalartAllmarasDES<BasicTurbulenceModel>::Omega
 (
-    const volTensorField& gradU
+    const volTensorField::Internal& gradU
 ) const
 {
-    return volScalarField::New
-    (
-        modelName("S"),
-        sqrt(2.0)*mag(symm(gradU))
-    );
-}
-
-
-template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::Omega
-(
-    const volTensorField& gradU
-) const
-{
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("Omega"),
         sqrt(2.0)*mag(skew(gradU))
@@ -104,21 +91,21 @@ tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::Omega
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::Stilda
+tmp<volScalarField::Internal> SpalartAllmarasDES<BasicTurbulenceModel>::Stilda
 (
-    const volScalarField& chi,
-    const volScalarField& fv1,
-    const volScalarField& Omega,
-    const volScalarField& dTilda
+    const volScalarField::Internal& chi,
+    const volScalarField::Internal& fv1,
+    const volScalarField::Internal& Omega,
+    const volScalarField::Internal& dTilda
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("Stilda"),
         max
         (
             Omega
-          + fv2(chi, fv1)*nuTilda_/sqr(kappa_*dTilda),
+          + fv2(chi, fv1)*nuTilda_()/sqr(kappa_*dTilda),
             Cs_*Omega
         )
     );
@@ -126,50 +113,44 @@ tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::Stilda
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::r
+tmp<volScalarField::Internal> SpalartAllmarasDES<BasicTurbulenceModel>::r
 (
-    const volScalarField& nur,
-    const volScalarField& Omega,
-    const volScalarField& dTilda
+    const volScalarField::Internal& nur,
+    const volScalarField::Internal& Omega,
+    const volScalarField::Internal& dTilda
 ) const
 {
-    tmp<volScalarField> tr
+    return volScalarField::Internal::New
     (
-        volScalarField::New
+        modelName("r"),
+        min
         (
-            modelName("r"),
-            min
-            (
-                nur
-               /(
-                   max
-                   (
-                       Omega,
-                       dimensionedScalar(Omega.dimensions(), small)
-                   )
-                  *sqr(kappa_*dTilda)
-               ),
-                scalar(10)
-            )
+            nur
+           /(
+                max
+                (
+                    Omega,
+                    dimensionedScalar(Omega.dimensions(), small)
+                )
+               *sqr(kappa_*dTilda)
+            ),
+            scalar(10)
         )
     );
-    tr.ref().boundaryFieldRef() == 0.0;
-
-    return tr;
 }
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::fw
+tmp<volScalarField::Internal> SpalartAllmarasDES<BasicTurbulenceModel>::fw
 (
-    const volScalarField& Omega,
-    const volScalarField& dTilda
+    const volScalarField::Internal& Omega,
+    const volScalarField::Internal& dTilda
 ) const
 {
-    const volScalarField r(this->r(nuTilda_, Omega, dTilda));
-    const volScalarField g(r + Cw2_*(pow6(r) - r));
+    const volScalarField::Internal r(this->r(nuTilda_, Omega, dTilda));
+    const volScalarField::Internal g(modelName("g"), r + Cw2_*(pow6(r) - r));
 
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("fw"),
         g*pow((1 + pow6(Cw3_))/(pow6(g) + pow6(Cw3_)), 1.0/6.0)
@@ -178,23 +159,35 @@ tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::fw
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::dTilda
+tmp<volScalarField::Internal> SpalartAllmarasDES<BasicTurbulenceModel>::dTilda
 (
-    const volScalarField& chi,
-    const volScalarField& fv1,
-    const volTensorField& gradU
+    const volScalarField::Internal& chi,
+    const volScalarField::Internal& fv1,
+    const volTensorField::Internal& gradU
 ) const
 {
-    tmp<volScalarField> tdTilda
+    return volScalarField::Internal::New
     (
-        volScalarField::New
-        (
-            modelName("dTilda"),
-            CDES_*this->delta()
-        )
+        modelName("dTilda"),
+        min(CDES_*this->delta()(), y_)
     );
-    min(tdTilda.ref().ref(), tdTilda(), y_);
-    return tdTilda;
+}
+
+
+template<class BasicTurbulenceModel>
+void SpalartAllmarasDES<BasicTurbulenceModel>::cacheLESRegion
+(
+    const volScalarField::Internal& dTilda
+) const
+{
+    if (this->mesh_.cacheTemporaryObject(modelName("LESRegion")))
+    {
+        volScalarField::Internal::New
+        (
+            modelName("LESRegion"),
+            neg(dTilda - y_())
+        );
+    }
 }
 
 
@@ -407,26 +400,43 @@ tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::k() const
 {
     const volScalarField chi(this->chi());
     const volScalarField fv1(this->fv1(chi));
-    return sqr(this->nut()/ck_/dTilda(chi, fv1, fvc::grad(this->U_)));
-}
 
+    volScalarField dTildaExtrapolated
+    (
+        IOobject
+        (
+            "dTildaExtrapolated",
+            this->mesh_.time().timeName(),
+            this->mesh_
+        ),
+        this->mesh_,
+        dimLength,
+        zeroGradientFvPatchScalarField::typeName
+    );
+    dTildaExtrapolated.ref() = dTilda(chi, fv1, fvc::grad(this->U_));
+    dTildaExtrapolated.correctBoundaryConditions();
 
-template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasDES<BasicTurbulenceModel>::LESRegion() const
-{
-    const volScalarField chi(this->chi());
-    const volScalarField fv1(this->fv1(chi));
-
-    tmp<volScalarField> tLESRegion
+    tmp<volScalarField> tk
     (
         volScalarField::New
         (
-            "DES::LESRegion",
-            neg(dTilda(chi, fv1, fvc::grad(this->U_)) - y_)
+            modelName("k"),
+            sqr(this->nut()/ck_/dTildaExtrapolated)
         )
     );
 
-    return tLESRegion;
+    const fvPatchList& patches = this->mesh_.boundary();
+    volScalarField::Boundary& kBf = tk.ref().boundaryFieldRef();
+
+    forAll(patches, patchi)
+    {
+        if (isA<wallFvPatch>(patches[patchi]))
+        {
+            kBf[patchi] = 0;
+        }
+    }
+
+    return tk;
 }
 
 
@@ -451,9 +461,13 @@ void SpalartAllmarasDES<BasicTurbulenceModel>::correct()
     const volScalarField fv1(this->fv1(chi));
 
     tmp<volTensorField> tgradU = fvc::grad(U);
-    const volScalarField Omega(this->Omega(tgradU()));
-    const volScalarField dTilda(this->dTilda(chi, fv1, tgradU()));
-    const volScalarField Stilda(this->Stilda(chi, fv1, Omega, dTilda));
+    const volScalarField::Internal Omega(this->Omega(tgradU()));
+    const volScalarField::Internal dTilda(this->dTilda(chi, fv1, tgradU()));
+    const volScalarField::Internal Stilda
+    (
+        this->Stilda(chi, fv1, Omega, dTilda)
+    );
+    tgradU.clear();
 
     tmp<fvScalarMatrix> nuTildaEqn
     (
@@ -462,10 +476,10 @@ void SpalartAllmarasDES<BasicTurbulenceModel>::correct()
       - fvm::laplacian(alpha*rho*DnuTildaEff(), nuTilda_)
       - Cb2_/sigmaNut_*alpha*rho*magSqr(fvc::grad(nuTilda_))
      ==
-        Cb1_*alpha*rho*Stilda*nuTilda_
+        Cb1_*alpha()*rho()*Stilda*nuTilda_()
       - fvm::Sp
         (
-            Cw1_*alpha*rho*fw(Stilda, dTilda)*nuTilda_/sqr(dTilda),
+            Cw1_*alpha()*rho()*fw(Stilda, dTilda)*nuTilda_()/sqr(dTilda),
             nuTilda_
         )
       + fvOptions(alpha, rho, nuTilda_)
@@ -479,6 +493,9 @@ void SpalartAllmarasDES<BasicTurbulenceModel>::correct()
     nuTilda_.correctBoundaryConditions();
 
     correctNut();
+
+    // Optionally cache the LESRegion field
+    cacheLESRegion(dTilda);
 }
 
 
diff --git a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.H b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.H
index ce78a4f248..746b66bbf7 100644
--- a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.H
+++ b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasDES/SpalartAllmarasDES.H
@@ -99,43 +99,50 @@ protected:
 
         tmp<volScalarField> fv1(const volScalarField& chi) const;
 
-        tmp<volScalarField> fv2
+        tmp<volScalarField::Internal> fv2
         (
-            const volScalarField& chi,
-            const volScalarField& fv1
+            const volScalarField::Internal& chi,
+            const volScalarField::Internal& fv1
         ) const;
 
-        tmp<volScalarField> S(const volTensorField& gradU) const;
-
-        tmp<volScalarField> Omega(const volTensorField& gradU) const;
-
-        tmp<volScalarField> Stilda
+        tmp<volScalarField::Internal> Omega
         (
-            const volScalarField& chi,
-            const volScalarField& fv1,
-            const volScalarField& Omega,
-            const volScalarField& dTilda
+            const volTensorField::Internal& gradU
         ) const;
 
-        tmp<volScalarField> r
+        tmp<volScalarField::Internal> Stilda
         (
-            const volScalarField& nur,
-            const volScalarField& Omega,
-            const volScalarField& dTilda
+            const volScalarField::Internal& chi,
+            const volScalarField::Internal& fv1,
+            const volScalarField::Internal& Omega,
+            const volScalarField::Internal& dTilda
         ) const;
 
-        tmp<volScalarField> fw
+        tmp<volScalarField::Internal> r
         (
-            const volScalarField& Omega,
-            const volScalarField& dTilda
+            const volScalarField::Internal& nur,
+            const volScalarField::Internal& Omega,
+            const volScalarField::Internal& dTilda
+        ) const;
+
+        tmp<volScalarField::Internal> fw
+        (
+            const volScalarField::Internal& Omega,
+            const volScalarField::Internal& dTilda
         ) const;
 
         //- Length scale
-        virtual tmp<volScalarField> dTilda
+        virtual tmp<volScalarField::Internal> dTilda
         (
-            const volScalarField& chi,
-            const volScalarField& fv1,
-            const volTensorField& gradU
+            const volScalarField::Internal& chi,
+            const volScalarField::Internal& fv1,
+            const volTensorField::Internal& gradU
+        ) const;
+
+        //- Cache the LES region indicator field
+        virtual void cacheLESRegion
+        (
+            const volScalarField::Internal& dTilda
         ) const;
 
         void correctNut(const volScalarField& fv1);
@@ -193,9 +200,6 @@ public:
             return nuTilda_;
         }
 
-        //- Return the LES field indicator
-        virtual tmp<volScalarField> LESRegion() const;
-
         //- Correct nuTilda and related properties
         virtual void correct();
 
diff --git a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.C b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.C
index 711ca8122f..fc495c6fe5 100644
--- a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.C
+++ b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.C
@@ -35,28 +35,24 @@ namespace LESModels
 // * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::alpha() const
+tmp<volScalarField::Internal>
+SpalartAllmarasIDDES<BasicTurbulenceModel>::IDDESalpha() const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("alpha"),
-        max
-        (
-            0.25
-          - this->y_/static_cast<const volScalarField&>(IDDESDelta_.hmax()),
-            scalar(-5)
-        )
+        max(0.25 - this->y_()/IDDESDelta_.hmax(), scalar(-5))
     );
 }
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::ft
+tmp<volScalarField::Internal> SpalartAllmarasIDDES<BasicTurbulenceModel>::ft
 (
-    const volScalarField& magGradU
+    const volScalarField::Internal& magGradU
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("ft"),
         tanh(pow3(sqr(ct_)*rd(this->nut_, magGradU)))
@@ -65,12 +61,12 @@ tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::ft
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::fl
+tmp<volScalarField::Internal> SpalartAllmarasIDDES<BasicTurbulenceModel>::fl
 (
-    const volScalarField& magGradU
+    const volScalarField::Internal& magGradU
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("fl"),
         tanh(pow(sqr(cl_)*rd(this->nu(), magGradU), 10))
@@ -79,13 +75,13 @@ tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::fl
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::rd
+tmp<volScalarField::Internal> SpalartAllmarasIDDES<BasicTurbulenceModel>::rd
 (
-    const volScalarField& nur,
-    const volScalarField& magGradU
+    const volScalarField::Internal& nur,
+    const volScalarField::Internal& magGradU
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("rd"),
         min
@@ -96,7 +92,7 @@ tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::rd
                (
                    magGradU,
                    dimensionedScalar(magGradU.dimensions(), small)
-               )*sqr(this->kappa_*this->y_)
+               )*sqr(this->kappa_*this->y_())
             ),
             scalar(10)
         )
@@ -105,12 +101,12 @@ tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::rd
 
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::fd
+tmp<volScalarField::Internal> SpalartAllmarasIDDES<BasicTurbulenceModel>::fd
 (
-    const volScalarField& magGradU
+    const volScalarField::Internal& magGradU
 ) const
 {
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("fd"),
         1 - tanh(pow3(8*rd(this->nuEff(), magGradU)))
@@ -121,28 +117,70 @@ tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::fd
 // * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
 
 template<class BasicTurbulenceModel>
-tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::dTilda
+tmp<volScalarField::Internal>
+SpalartAllmarasIDDES<BasicTurbulenceModel>::dTilda
 (
-    const volScalarField& chi,
-    const volScalarField& fv1,
-    const volTensorField& gradU
+    const volScalarField::Internal& chi,
+    const volScalarField::Internal& fv1,
+    const volTensorField::Internal& gradU
 ) const
 {
-    const volScalarField alpha(this->alpha());
-    const volScalarField expTerm(exp(sqr(alpha)));
-    const volScalarField magGradU(mag(gradU));
+    const volScalarField::Internal alpha(IDDESalpha());
 
-    tmp<volScalarField> fHill =
-        2*(pos0(alpha)*pow(expTerm, -11.09) + neg(alpha)*pow(expTerm, -9.0));
+    const volScalarField::Internal expTerm
+    (
+        modelName("expTerm"),
+        exp(sqr(alpha))
+    );
 
-    tmp<volScalarField> fStep = min(2*pow(expTerm, -9.0), scalar(1));
-    const volScalarField fHyb(max(1 - fd(magGradU), fStep));
-    tmp<volScalarField> fAmp = 1 - max(ft(magGradU), fl(magGradU));
-    tmp<volScalarField> fRestore = max(fHill - 1, scalar(0))*fAmp;
+    const volScalarField::Internal magGradU(modelName("magGradU"), mag(gradU));
+
+    tmp<volScalarField::Internal> fHill
+    (
+        volScalarField::Internal::New
+        (
+            modelName("fHill"),
+            2*(pos0(alpha)*pow(expTerm, -11.09) + neg(alpha)*pow(expTerm, -9.0))
+        )
+    );
+
+    tmp<volScalarField::Internal> fStep
+    (
+        volScalarField::Internal::New
+        (
+            modelName("fStep"),
+            min(2*pow(expTerm, -9.0), scalar(1))
+        )
+    );
+
+    const volScalarField::Internal fHyb
+    (
+        modelName("fHyb"),
+        max(1 - fd(magGradU), fStep)
+    );
+
+    tmp<volScalarField::Internal> fAmp
+    (
+        volScalarField::Internal::New
+        (
+            modelName("fAmp"),
+            1 - max(ft(magGradU), fl(magGradU))
+        )
+    );
+
+    tmp<volScalarField::Internal> fRestore
+    (
+        volScalarField::Internal::New
+        (
+            modelName("fRestore"),
+            max(fHill - 1, scalar(0))*fAmp
+        )
+    );
 
     // IGNORING ft2 terms
-    const volScalarField Psi
+    const volScalarField::Internal Psi
     (
+        modelName("Psi"),
         sqrt
         (
             min
@@ -157,7 +195,7 @@ tmp<volScalarField> SpalartAllmarasIDDES<BasicTurbulenceModel>::dTilda
         )
     );
 
-    return volScalarField::New
+    return volScalarField::Internal::New
     (
         modelName("dTilda"),
         max
diff --git a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.H b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.H
index e9a1281985..67e4ff650a 100644
--- a/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.H
+++ b/src/TurbulenceModels/turbulenceModels/LES/SpalartAllmarasIDDES/SpalartAllmarasIDDES.H
@@ -78,18 +78,29 @@ class SpalartAllmarasIDDES
 
     // Private Member Functions
 
-        tmp<volScalarField> alpha() const;
-        tmp<volScalarField> ft(const volScalarField& magGradU) const;
-        tmp<volScalarField> fl(const volScalarField& magGradU) const;
+        tmp<volScalarField::Internal> IDDESalpha() const;
 
-        tmp<volScalarField> rd
+        tmp<volScalarField::Internal> ft
         (
-            const volScalarField& nur,
-            const volScalarField& magGradU
+            const volScalarField::Internal& magGradU
+        ) const;
+
+        tmp<volScalarField::Internal> fl
+        (
+            const volScalarField::Internal& magGradU
+        ) const;
+
+        tmp<volScalarField::Internal> rd
+        (
+            const volScalarField::Internal& nur,
+            const volScalarField::Internal& magGradU
         ) const;
 
         //- Delay function
-        tmp<volScalarField> fd(const volScalarField& magGradU) const;
+        tmp<volScalarField::Internal> fd
+        (
+            const volScalarField::Internal& magGradU
+        ) const;
 
 
 protected:
@@ -99,11 +110,11 @@ protected:
         using IOobject::modelName;
 
         //- Length scale
-        virtual tmp<volScalarField> dTilda
+        virtual tmp<volScalarField::Internal> dTilda
         (
-            const volScalarField& chi,
-            const volScalarField& fv1,
-            const volTensorField& gradU
+            const volScalarField::Internal& chi,
+            const volScalarField::Internal& fv1,
+            const volTensorField::Internal& gradU
         ) const;
 
 
diff --git a/tutorials/incompressible/pisoFoam/LES/motorBike/lesFiles/controlDict b/tutorials/incompressible/pisoFoam/LES/motorBike/lesFiles/controlDict
index db67f245b2..fde7eb1ddf 100644
--- a/tutorials/incompressible/pisoFoam/LES/motorBike/lesFiles/controlDict
+++ b/tutorials/incompressible/pisoFoam/LES/motorBike/lesFiles/controlDict
@@ -44,8 +44,27 @@ timePrecision   6;
 
 runTimeModifiable true;
 
+cacheTemporaryObjects
+(
+    SpalartAllmarasDDES:LESRegion
+);
+
 functions
 {
+    writeCachedObjects
+    {
+        type        writeObjects;
+        libs        ("libutilityFunctionObjects.so");
+
+        writeControl writeTime;
+        writeOption anyWrite;
+
+        objects
+        (
+            SpalartAllmarasDDES:LESRegion
+        );
+    }
+
     #include "cuttingPlane"
     #include "streamLines"
     #include "forceCoeffs"