HerschelBulkley: Changed the definition of the coefficients and stress to more commonly used forms.

This does not change the form of the function but the coefficients must be set appropriately.

src/transportModels/incompressible/viscosityModels/HerschelBulkley/HerschelBulkley.C

@@ -52,10 +52,28 @@ Foam::viscosityModels::HerschelBulkley::calcNu() const
 {
     dimensionedScalar tone("tone", dimTime, 1.0);
     dimensionedScalar rtone("rtone", dimless/dimTime, 1.0);
+
     tmp<volScalarField> sr(strainRate());
-    return (min(nu0_,(tau0_ + k_* rtone *( pow(tone * sr(), n_)
-        - pow(tone*tau0_/nu0_,n_))) / (max(sr(), dimensionedScalar
-        ("VSMALL", dimless/dimTime, VSMALL)))));
+
+ // return
+ // (
+ //     min
+ //     (
+ //         nu0_,
+ //         (tau0_ + k_*rtone*(pow(tone*sr(), n_) - pow(tone*tau0_/nu0_, n_)))
+ //        /max(sr(), dimensionedScalar("VSMALL", dimless/dimTime, VSMALL))
+ //     )
+ // );
+
+    return
+    (
+        min
+        (
+            nu0_,
+            (tau0_ + k_*rtone*pow(tone*sr(), n_))
+           /(max(sr(), dimensionedScalar ("VSMALL", dimless/dimTime, VSMALL)))
+        )
+    );
 }
 
 

src/transportModels/incompressible/viscosityModels/viscosityModel/viscosityModel.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2004-2010 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2004-2011 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -57,7 +57,7 @@ Foam::viscosityModel::viscosityModel
 
 Foam::tmp<Foam::volScalarField> Foam::viscosityModel::strainRate() const
 {
-    return mag(symm(fvc::grad(U_)));
+    return sqrt(2.0)*mag(symm(fvc::grad(U_)));
 }