updated particle forces

src/lagrangian/intermediate/clouds/Templates/KinematicCloud/KinematicCloud.C

@@ -177,6 +177,7 @@ template<class ParcelType>
 void Foam::KinematicCloud<ParcelType>::preEvolve()
 {
     this->dispersion().cacheFields(true);
+    forces_.cacheFields(true);
 }
 
 
@@ -189,6 +190,7 @@ void Foam::KinematicCloud<ParcelType>::postEvolve()
     }
 
     this->dispersion().cacheFields(false);
+    forces_.cacheFields(false);
 
     this->postProcessing().post();
 }

src/lagrangian/intermediate/clouds/Templates/KinematicCloud/KinematicCloud.H

@@ -274,18 +274,6 @@ public:
                 inline const dictionary& interpolationSchemes() const;
 
 
-            // Forces to include in particle motion evaluation
-
-                //- Return reference to the gravity force flag
-                inline Switch forceGravity() const;
-
-                //- Return reference to the virtual mass force flag
-                inline Switch forceVirtualMass() const;
-
-                //- Return reference to the pressure gradient force flag
-                inline Switch forcePressureGradient() const;
-
-
             // Sub-models
 
                 //- Return const-access to the dispersion model

src/lagrangian/intermediate/particleForces/particleForces.C

@@ -27,6 +27,7 @@ License
 #include "particleForces.H"
 #include "fvMesh.H"
 #include "volFields.H"
+#include "fvcGrad.H"
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
@@ -40,21 +41,17 @@ Foam::particleForces::particleForces
     mesh_(mesh),
     dict_(dict.subDict("particleForces")),
     g_(g),
+    gradUPtr_(NULL),
     gravity_(dict_.lookup("gravity")),
     virtualMass_(dict_.lookup("virtualMass")),
     Cvm_(0.0),
     pressureGradient_(dict_.lookup("pressureGradient")),
-    gradUName_("unknown_gradUName")
+    UName_(dict_.lookupOrDefault<word>("U", "U"))
 {
-    if (gravity_)
+    if (virtualMass_)
     {
         dict_.lookup("Cvm") >> Cvm_;
     }
-
-    if (pressureGradient_)
-    {
-        dict_.lookup("gradU") >> gradUName_;
-    }
 }
 
 
@@ -63,18 +60,21 @@ Foam::particleForces::particleForces(const particleForces& f)
     mesh_(f.mesh_),
     dict_(f.dict_),
     g_(f.g_),
+    gradUPtr_(f.gradUPtr_),
     gravity_(f.gravity_),
     virtualMass_(f.virtualMass_),
     Cvm_(f.Cvm_),
     pressureGradient_(f.pressureGradient_),
-    gradUName_(f.gradUName_)
+    UName_(f.UName_)
 {}
 
 
 // * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
 Foam::particleForces::~particleForces()
-{}
+{
+    cacheFields(false);
+}
 
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
@@ -109,9 +109,26 @@ Foam::Switch Foam::particleForces::pressureGradient() const
 }
 
 
-const Foam::word& Foam::particleForces::gradUName() const
+const Foam::word& Foam::particleForces::UName() const
 {
-    return gradUName_;
+    return UName_;
+}
+
+
+void Foam::particleForces::cacheFields(const bool store)
+{
+    if (store && pressureGradient_)
+    {
+        const volVectorField U = mesh_.lookupObject<volVectorField>(UName_);
+        gradUPtr_ = fvc::grad(U).ptr();
+    }
+    else
+    {
+        if (gradUPtr_)
+        {
+            delete gradUPtr_;
+        }
+    }
 }
 
 
@@ -130,15 +147,17 @@ Foam::vector Foam::particleForces::calcCoupled
     // Virtual mass force
     if (virtualMass_)
     {
-        notImplemented("Foam::particleForces::calc(...) - virtualMass force");
+        notImplemented
+        (
+            "Foam::particleForces::calcCoupled(...) - virtual mass force"
+        );
 //        Ftot += Cvm_*rhoc/rho*d(Uc - U)/dt;
     }
 
     // Pressure gradient force
     if (pressureGradient_)
     {
-        const volSymmTensorField& gradU =
-            mesh_.lookupObject<volSymmTensorField>(gradUName_);
+        const volTensorField& gradU = *gradUPtr_;
         Ftot += rhoc/rho*(U & gradU[cellI]);
     }
 

src/lagrangian/intermediate/particleForces/particleForces.H

@@ -39,6 +39,7 @@ SourceFiles
 #include "dictionary.H"
 #include "Switch.H"
 #include "vector.H"
+#include "volFieldsFwd.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -65,6 +66,9 @@ class particleForces
         //- Gravity
         const vector g_;
 
+        //- Velocity gradient field
+        const volTensorField* gradUPtr_;
+
 
         // Forces to include in particle motion evaluation
 
@@ -80,8 +84,11 @@ class particleForces
             //- Pressure gradient
             Switch pressureGradient_;
 
-            //- Name of velocity gradient field for pressure gradient force
-            word gradUName_;
+
+        // Additional info
+
+            //- Name of velucity field - default = "U"
+            const word UName_;
 
 
 public:
@@ -126,12 +133,15 @@ public:
             //- Return pressure gradient force activate switch
             Switch pressureGradient() const;
 
-            //- Return the name of the velocity gradient field
-            const word& gradUName() const;
+            //- Return name of velocity field
+            const word& UName() const;
 
 
        // Evaluation
 
+            //- Cache carrier fields
+            void cacheFields(const bool store);
+
             //- Calculate action/reaction forces between carrier and particles
             vector calcCoupled
             (

tutorials/lagrangian/coalChemistryFoam/simplifiedSiwek/constant/coalCloud1Properties

@@ -80,9 +80,7 @@ particleForces
 {
     gravity         on;
     virtualMass     off;
-    Cvm             0.5;
     pressureGradient off;
-    gradU           gradU;
 }
 
 ManualInjectionCoeffs

tutorials/lagrangian/coalChemistryFoam/simplifiedSiwek/constant/limestoneCloud1Properties

@@ -66,9 +66,7 @@ particleForces
 {
     gravity         on;
     virtualMass     off;
-    Cvm             0.5;
     pressureGradient off;
-    gradU           gradU;
 }
 
 ManualInjectionCoeffs

tutorials/lagrangian/porousExplicitSourceReactingParcelFoam/filter/constant/reactingCloud1Properties

@@ -74,9 +74,7 @@ particleForces
 {
     gravity         on;
     virtualMass     off;
-    Cvm             0.5;
     pressureGradient off;
-    gradU           gradU;
 }
 
 ManualInjectionCoeffs

tutorials/lagrangian/reactingParcelFoam/evaporationTest/constant/reactingCloud1Properties

@@ -74,9 +74,7 @@ particleForces
 {
     gravity         on;
     virtualMass     off;
-    Cvm             0.5;
     pressureGradient off;
-    gradU           gradU;
 }
 
 ManualInjectionCoeffs

tutorials/lagrangian/rhoPisoTwinParcelFoam/simplifiedSiwek/constant/kinematicCloud1Properties

@@ -54,9 +54,7 @@ particleForces
 {
     gravity         on;
     virtualMass     off;
-    Cvm             0.5;
     pressureGradient off;
-    gradU           gradU;
 }
 
 ManualInjectionCoeffs

tutorials/lagrangian/rhoPisoTwinParcelFoam/simplifiedSiwek/constant/thermoCloud1Properties

@@ -66,9 +66,7 @@ particleForces
 {
     gravity         on;
     virtualMass     off;
-    Cvm             0.5;
     pressureGradient off;
-    gradU           gradU;
 }
 
 ManualInjectionCoeffs