diff --git a/src/lagrangian/intermediate/Make/files b/src/lagrangian/intermediate/Make/files
index f3a6866a97..9165621d6c 100644
--- a/src/lagrangian/intermediate/Make/files
+++ b/src/lagrangian/intermediate/Make/files
@@ -48,6 +48,7 @@ $(RADIATION)/absorptionEmission/cloudAbsorptionEmission/cloudAbsorptionEmission.
 $(RADIATION)/scatter/cloudScatter/cloudScatter.C
 
 submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.C
+submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C
 
 KINEMATICINJECTION=submodels/Kinematic/InjectionModel
 $(KINEMATICINJECTION)/KinematicLookupTableInjection/kinematicParcelInjectionData.C
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.C b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.C
index 56a9ce61a6..20d8997b22 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.C
@@ -33,9 +33,9 @@ Foam::label Foam::LocalInteraction<CloudType>::applyToPatch
     const label globalPatchI
 ) const
 {
-    forAll(patchIds_, patchI)
+    forAll(patchIDs_, patchI)
     {
-        if (patchIds_[patchI] == globalPatchI)
+        if (patchIDs_[patchI] == globalPatchI)
         {
             return patchI;
         }
@@ -130,8 +130,8 @@ Foam::LocalInteraction<CloudType>::LocalInteraction
 )
 :
     PatchInteractionModel<CloudType>(dict, cloud, typeName),
-    patchData_(this->coeffDict().lookup("patches")),
-    patchIds_(patchData_.size()),
+    patchData_(cloud.mesh(), this->coeffDict().lookup("patches")),
+    patchIDs_(patchData_.size()),
     nEscape0_(patchData_.size(), 0),
     massEscape0_(patchData_.size(), 0.0),
     nStick0_(patchData_.size(), 0),
@@ -141,44 +141,6 @@ Foam::LocalInteraction<CloudType>::LocalInteraction
     nStick_(patchData_.size(), 0),
     massStick_(patchData_.size(), 0.0)
 {
-    const polyMesh& mesh = cloud.mesh();
-    const polyBoundaryMesh& bMesh = mesh.boundaryMesh();
-
-    // check that user patches are valid region patches
-    forAll(patchData_, patchI)
-    {
-        const word& patchName = patchData_[patchI].patchName();
-        patchIds_[patchI] = bMesh.findPatchID(patchName);
-        if (patchIds_[patchI] < 0)
-        {
-            FatalErrorIn("LocalInteraction(const dictionary&, CloudType&)")
-                << "Patch " << patchName << " not found. Available patches "
-                << "are: " << bMesh.names() << nl << exit(FatalError);
-        }
-    }
-
-    // check that all walls are specified
-    DynamicList<word> badWalls;
-    forAll(bMesh, patchI)
-    {
-        if
-        (
-            isA<wallPolyPatch>(bMesh[patchI])
-         && applyToPatch(bMesh[patchI].index()) < 0
-        )
-        {
-            badWalls.append(bMesh[patchI].name());
-        }
-    }
-
-    if (badWalls.size() > 0)
-    {
-        FatalErrorIn("LocalInteraction(const dictionary&, CloudType&)")
-            << "All wall patches must be specified when employing local patch "
-            << "interaction. Please specify data for patches:" << nl
-            << badWalls << nl << exit(FatalError);
-    }
-
     // check that interactions are valid/specified
     forAll(patchData_, patchI)
     {
@@ -211,7 +173,7 @@ Foam::LocalInteraction<CloudType>::LocalInteraction
 :
     PatchInteractionModel<CloudType>(pim),
     patchData_(pim.patchData_),
-    patchIds_(pim.patchIds_),
+    patchIDs_(pim.patchIDs_),
     nEscape0_(pim.nEscape0_),
     massEscape0_(pim.massEscape0_),
     nStick0_(pim.nStick0_),
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.H b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.H
index 42b641aeab..5d6962b595 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/LocalInteraction.H
@@ -33,7 +33,7 @@ Description
 #define LocalInteraction_H
 
 #include "PatchInteractionModel.H"
-#include "patchInteractionData.H"
+#include "patchInteractionDataList.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -51,10 +51,10 @@ class LocalInteraction
     // Private data
 
         //- List of participating patches
-        const List<patchInteractionData> patchData_;
+        const patchInteractionDataList patchData_;
 
         //- List of participating patch ids
-        List<label> patchIds_;
+        List<label> patchIDs_;
 
 
         // Counters for initial particle fates
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C
new file mode 100644
index 0000000000..566287eca0
--- /dev/null
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C
@@ -0,0 +1,130 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2011-2011 OpenCFD Ltd.
+     \\/     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 "patchInteractionDataList.H"
+#include "stringListOps.H"
+#include "wallPolyPatch.H"
+
+// * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * * //
+
+Foam::patchInteractionDataList::patchInteractionDataList()
+:
+    List<patchInteractionData>(),
+    patchGroupIDs_()
+{}
+
+
+Foam::patchInteractionDataList::patchInteractionDataList
+(
+    const polyMesh& mesh,
+    const dictionary& dict
+)
+:
+    List<patchInteractionData>(dict.lookup("patches")),
+    patchGroupIDs_(this->size())
+{
+    const polyBoundaryMesh& bMesh = mesh.boundaryMesh();
+    const wordList allPatchNames = bMesh.names();
+
+    const List<patchInteractionData>& items = *this;
+    forAllReverse(items, i)
+    {
+        const word& patchName = items[i].patchName();
+        labelList patchIDs = findStrings(patchName, allPatchNames);
+
+        if (patchIDs.empty())
+        {
+            WarningIn
+            (
+                "Foam::patchInteractionDataList::patchInteractionDataList"
+                "("
+                    "const polyMesh&, "
+                    "const dictionary&"
+                ")"
+            )   << "Cannot find any patch names matching " << patchName
+                << endl;
+        }
+
+        patchGroupIDs_[i].transfer(patchIDs);
+    }
+
+    // check that all walls are specified
+    DynamicList<word> badWalls;
+    forAll(bMesh, patchI)
+    {
+        const polyPatch& pp = bMesh[patchI];
+        if (isA<wallPolyPatch>(pp) && applyToPatch(pp.index()) < 0)
+        {
+            badWalls.append(pp.name());
+        }
+    }
+
+    if (badWalls.size() > 0)
+    {
+        FatalErrorIn
+        (
+            "Foam::patchInteractionDataList::patchInteractionDataList"
+            "("
+                "const polyMesh&, "
+                "const dictionary&"
+            ")"
+        )    << "All wall patches must be specified when employing local patch "
+            << "interaction. Please specify data for patches:" << nl
+            << badWalls << nl << exit(FatalError);
+    }
+}
+
+
+Foam::patchInteractionDataList::patchInteractionDataList
+(
+    const patchInteractionDataList& pidl
+)
+:
+    List<patchInteractionData>(pidl),
+    patchGroupIDs_(pidl.patchGroupIDs_)
+{}
+
+
+// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
+
+Foam::label Foam::patchInteractionDataList::applyToPatch(const label id) const
+{
+    forAll(patchGroupIDs_, groupI)
+    {
+        const labelList& patchIDs = patchGroupIDs_[groupI];
+        forAll(patchIDs, patchI)
+        {
+            if (patchIDs[patchI] == id)
+            {
+                return groupI;
+            }
+        }
+    }
+
+    return -1;
+}
+
+
+// ************************************************************************* //
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.H b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.H
new file mode 100644
index 0000000000..6c48ea735d
--- /dev/null
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.H
@@ -0,0 +1,90 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2011-2011 OpenCFD Ltd.
+     \\/     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/>.
+
+Class
+    Foam::patchInteractionDataList
+
+Description
+    List container for patchInteractionData class
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef patchInteractionDataList_H
+#define patchInteractionDataList_H
+
+#include "patchInteractionData.H"
+#include "polyMesh.H"
+#include "dictionary.H"
+#include "labelList.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+/*---------------------------------------------------------------------------*\
+                  Class patchInteractionDataList Declaration
+\*---------------------------------------------------------------------------*/
+
+class patchInteractionDataList
+:
+    public List<patchInteractionData>
+{
+private:
+
+    // Private data
+
+        //- List of patch IDs for each patch group
+        labelListList patchGroupIDs_;
+
+
+public:
+
+    // Constructor
+
+        //- Construct null
+        patchInteractionDataList();
+
+        //- Construct copy
+        patchInteractionDataList(const patchInteractionDataList& pidl);
+
+        //- Construct from Istream
+        patchInteractionDataList(const polyMesh& mesh, const dictionary& dict);
+
+
+    // Member functions
+
+        //- Return label of group containing patch id
+        //  Returns -1 if patch id is not present
+        label applyToPatch(const label id) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.C b/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.C
index e87f37e727..550a9d54c7 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2008-2010 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2008-2011 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -25,6 +25,7 @@ License
 
 #include "PatchPostProcessing.H"
 #include "Pstream.H"
+#include "stringListOps.H"
 #include "ListListOps.H"
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
@@ -35,12 +36,15 @@ Foam::label Foam::PatchPostProcessing<CloudType>::applyToPatch
     const label globalPatchI
 ) const
 {
-    forAll(patchIds_, patchI)
+    label patchI = 0;
+    forAllConstIter(labelHashSet, patchIDs_, iter)
     {
-        if (patchIds_[patchI] == globalPatchI)
+        if (iter.key() == globalPatchI)
         {
             return patchI;
         }
+
+        patchI++;
     }
 
     return -1;
@@ -52,16 +56,18 @@ Foam::label Foam::PatchPostProcessing<CloudType>::applyToPatch
 template<class CloudType>
 void Foam::PatchPostProcessing<CloudType>::write()
 {
-    forAll(patchData_, patchI)
+    forAll(patchData_, i)
     {
         List<List<string> > procData(Pstream::nProcs());
-        procData[Pstream::myProcNo()] = patchData_[patchI];
+        procData[Pstream::myProcNo()] = patchData_[i];
 
         Pstream::gatherList(procData);
 
         if (Pstream::master())
         {
-            fileName outputDir = this->owner().time().path();
+            const fvMesh& mesh = this->owner().mesh();
+
+            fileName outputDir = mesh.time().path();
 
             if (Pstream::parRun())
             {
@@ -69,24 +75,26 @@ void Foam::PatchPostProcessing<CloudType>::write()
                 // distributed data running)
                 outputDir =
                     outputDir/".."/"postProcessing"/cloud::prefix/
-                    this->owner().name()/this->owner().time().timeName();
+                    this->owner().name()/mesh.time().timeName();
             }
             else
             {
                 outputDir =
                     outputDir/"postProcessing"/cloud::prefix/
-                    this->owner().name()/this->owner().time().timeName();
+                    this->owner().name()/mesh.time().timeName();
             }
 
             // Create directory if it doesn't exist
             mkDir(outputDir);
 
+            const word& patchName = mesh.boundaryMesh()[patchIDs_[i]].name();
+
             OFstream patchOutFile
             (
-                outputDir/patchNames_[patchI] + ".post",
+                outputDir/patchName + ".post",
                 IOstream::ASCII,
                 IOstream::currentVersion,
-                this->owner().time().writeCompression()
+                mesh.time().writeCompression()
             );
 
             List<string> globalData;
@@ -99,13 +107,13 @@ void Foam::PatchPostProcessing<CloudType>::write()
 
             patchOutFile<< "# Time " + parcelType::propHeader << nl;
 
-            forAll(globalData, i)
+            forAll(globalData, dataI)
             {
-                patchOutFile<< globalData[i].c_str() << nl;
+                patchOutFile<< globalData[dataI].c_str() << nl;
             }
         }
 
-        patchData_[patchI].clearStorage();
+        patchData_[i].clearStorage();
     }
 }
 
@@ -121,29 +129,36 @@ Foam::PatchPostProcessing<CloudType>::PatchPostProcessing
 :
     PostProcessingModel<CloudType>(dict, owner, typeName),
     maxStoredParcels_(readLabel(this->coeffDict().lookup("maxStoredParcels"))),
-    patchNames_(this->coeffDict().lookup("patches")),
-    patchData_(patchNames_.size()),
-    patchIds_(patchNames_.size())
+    patchIDs_(),
+    patchData_()
 {
-    const polyBoundaryMesh& bMesh = this->owner().mesh().boundaryMesh();
-    forAll(patchNames_, patchI)
+    const wordList allPatchNames = owner.mesh().boundaryMesh().names();
+    wordList patchName(this->coeffDict().lookup("patches"));
+
+    forAllReverse(patchName, i)
     {
-        const label id = bMesh.findPatchID(patchNames_[patchI]);
-        if (id < 0)
+        labelList patchIDs = findStrings(patchName[i], allPatchNames);
+
+        if (patchIDs.empty())
         {
-            FatalErrorIn
+            WarningIn
             (
-                "PatchPostProcessing<CloudType>::PatchPostProcessing"
+                "Foam::PatchPostProcessing<CloudType>::PatchPostProcessing"
                 "("
                     "const dictionary&, "
-                    "CloudType& owner"
+                    "CloudType& "
                 ")"
-            )<< "Requested patch " << patchNames_[patchI] << " not found" << nl
-             << "Available patches are: " << bMesh.names() << nl
-             << exit(FatalError);
+            )   << "Cannot find any patch names matching " << patchName[i]
+                << endl;
+        }
+
+        forAll(patchIDs, j)
+        {
+            patchIDs_.insert(patchIDs[j]);
         }
-        patchIds_[patchI] = id;
     }
+
+    patchData_.setSize(patchIDs_.size());
 }
 
 
@@ -155,9 +170,8 @@ Foam::PatchPostProcessing<CloudType>::PatchPostProcessing
 :
     PostProcessingModel<CloudType>(ppm),
     maxStoredParcels_(ppm.maxStoredParcels_),
-    patchNames_(ppm.patchNames_),
-    patchData_(ppm.patchData_),
-    patchIds_(ppm.patchIds_)
+    patchIDs_(ppm.patchIDs_),
+    patchData_(ppm.patchData_)
 {}
 
 
@@ -177,8 +191,8 @@ void Foam::PatchPostProcessing<CloudType>::postPatch
     const label patchI
 )
 {
-    label localPatchI = applyToPatch(patchI);
-    if (localPatchI >= 0 && patchData_[localPatchI].size() < maxStoredParcels_)
+    const label localPatchI = applyToPatch(patchI);
+    if (localPatchI != -1 && patchData_[localPatchI].size() < maxStoredParcels_)
     {
         OStringStream data;
         data<< this->owner().time().timeName() << ' ' << p;
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.H b/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.H
index df075084d4..32847c1b12 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessing.H
@@ -58,15 +58,12 @@ class PatchPostProcessing
         //- Maximum number of parcels to store
         label maxStoredParcels_;
 
-        //- List of patch names
-        wordList patchNames_;
+        //- List of patch indices to post-process
+        labelHashSet patchIDs_;
 
         //- List of output data per patch
         List<DynamicList<string> > patchData_;
 
-        //- Mapping from local to global patch ids
-        labelList patchIds_;
-
 
     // Private Member Functions
 
@@ -117,11 +114,8 @@ public:
             //- Return maximum number of parcels to store per patch
             inline label maxStoredParcels() const;
 
-            //- Return const access to the list of patch names
-            inline const wordList& patchNames() const;
-
             //- Return const mapping from local to global patch ids
-            inline const labelList& patchIds() const;
+            inline const labelList& patchIDs() const;
 
 
         // Evaluation
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessingI.H b/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessingI.H
index 3415904d3c..5cd4f5b255 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessingI.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PostProcessingModel/PatchPostProcessing/PatchPostProcessingI.H
@@ -31,17 +31,9 @@ Foam::label Foam::PatchPostProcessing<CloudType>::maxStoredParcels() const
 
 
 template<class CloudType>
-const Foam::wordList& Foam::PatchPostProcessing<CloudType>::patchNames() const
+const Foam::labelList& Foam::PatchPostProcessing<CloudType>::patchIDs() const
 {
-    return patchNames_;
-}
-
-
-template<class CloudType>
-const Foam::labelList&
-Foam::PatchPostProcessing<CloudType>::patchIds() const
-{
-    return patchIds_;
+    return patchIDs_;
 }