diff --git a/applications/utilities/postProcessing/velocityField/Q/Q.C b/applications/utilities/postProcessing/velocityField/Q/Q.C
index 74de3084b55abc9d455d240982be6ba9acab1804..0f9c6d8d8cbd4914291f1ca2f5f6d176bf03be98 100644
--- a/applications/utilities/postProcessing/velocityField/Q/Q.C
+++ b/applications/utilities/postProcessing/velocityField/Q/Q.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2012 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -27,6 +27,8 @@ Application
 Description
     Calculates and writes the second invariant of the velocity gradient tensor.
 
+        Q = 0.5*(sqr(tr(gradU)) - tr(((gradU)&(gradU))))      [1/s^2]
+
     The -noWrite option just outputs the max/min values without writing
     the field.
 
diff --git a/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.C b/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.C
index 5ec597f9bfe0495d2e2cf3bf868d1e299999943b..b4d1e30c87598b66769131787405f64d7b360e5a 100644
--- a/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.C
+++ b/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.C
@@ -34,9 +34,16 @@ defineTypeNameAndDebug(Foam::pressureCoefficient, 0);
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
-Foam::tmp<Foam::volScalarField> Foam::pressureCoefficient::rho() const
+Foam::tmp<Foam::volScalarField> Foam::pressureCoefficient::rho
+(
+    const volScalarField& p
+) const
 {
-    if (rhoName_ == "rhoInf")
+    if (p.dimensions() == dimPressure)
+    {
+        return(obr_.lookupObject<volScalarField>(rhoName_));
+    }
+    else
     {
         const fvMesh& mesh = refCast<const fvMesh>(obr_);
 
@@ -51,14 +58,10 @@ Foam::tmp<Foam::volScalarField> Foam::pressureCoefficient::rho() const
                     mesh
                 ),
                 mesh,
-                dimensionedScalar("rho", dimDensity, rhoRef_)
+                dimensionedScalar("rho", dimless, 1.0)
             )
         );
     }
-    else
-    {
-        return(obr_.lookupObject<volScalarField>(rhoName_));
-    }
 }
 
 
@@ -76,8 +79,7 @@ Foam::pressureCoefficient::pressureCoefficient
     obr_(obr),
     active_(true),
     pName_("p"),
-    rhoName_(word::null),
-    rhoRef_(-GREAT),
+    rhoName_("rho"),
     magUinf_(0.0)
 {
     // Check if the available mesh is an fvMesh, otherwise deactivate
@@ -114,12 +116,7 @@ void Foam::pressureCoefficient::read(const dictionary& dict)
     if (active_)
     {
         pName_ = dict.lookupOrDefault<word>("pName", "p");
-
         rhoName_ = dict.lookupOrDefault<word>("rhoName", "rho");
-        if (rhoName_ == "rhoInf")
-        {
-            dict.lookup("rhoInf") >> rhoRef_;
-        }
 
         dict.lookup("magUinf") >> magUinf_;
     }
@@ -153,7 +150,7 @@ void Foam::pressureCoefficient::write()
                 obr_,
                 IOobject::NO_READ
             ),
-            p/(0.5*rho()*sqr(magUinf_))
+            p/(0.5*rho(p)*sqr(magUinf_))
         );
 
         pressureCoefficient.write();
diff --git a/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.H b/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.H
index aaf0ca499b35f28b86e0e874d45a4099be6055a4..5f0379aa7f520c95c163385a2690bc3091522d29 100644
--- a/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.H
+++ b/src/postProcessing/functionObjects/utilities/pressureCoefficient/pressureCoefficient.H
@@ -77,21 +77,15 @@ class pressureCoefficient
         //- Name of density field (optional)
         word rhoName_;
 
-        //- Reference density needed for incompressible calculations [kg/m3]
-        scalar rhoRef_;
-
         //- Free stream velocity magnitude [m/s]
         scalar magUinf_;
 
 
     // Private Member Functions
 
-        //- Return rho if rhoName is specified otherwise rhoRef
-        tmp<volScalarField> rho() const;
-
-        //- Return rhoRef if the pressure field is dynamic, i.e. p/rho
-        //  otherwise return 1
-        scalar rho(const volScalarField& p) const;
+        //- Return 1 if the pressure field is kinematic, i.e. p/rho
+        //  otherwise return rho from database
+        tmp<volScalarField> rho(const volScalarField& p) const;
 
         //- Disallow default bitwise copy construct
         pressureCoefficient(const pressureCoefficient&);