From 179b6976b5ce5973d74350b634de1c07d2a3e6e6 Mon Sep 17 00:00:00 2001
From: Henry <Henry>
Date: Mon, 23 Jan 2012 10:14:58 +0000
Subject: [PATCH] compressible Smagorinsky SGS model: corrected calculation of
 k in k()

---
 .../compressible/LES/Smagorinsky/Smagorinsky.H         | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/turbulenceModels/compressible/LES/Smagorinsky/Smagorinsky.H b/src/turbulenceModels/compressible/LES/Smagorinsky/Smagorinsky.H
index f0bc077531..947b49fa75 100644
--- a/src/turbulenceModels/compressible/LES/Smagorinsky/Smagorinsky.H
+++ b/src/turbulenceModels/compressible/LES/Smagorinsky/Smagorinsky.H
@@ -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
@@ -113,7 +113,13 @@ public:
         //  calculated from the given velocity gradient
         tmp<volScalarField> k(const tmp<volTensorField>& gradU) const
         {
-            return (2.0*ck_/ce_)*sqr(delta())*magSqr(dev(symm(gradU)));
+            volSymmTensorField D(symm(gradU));
+
+            volScalarField a(ce_/delta());
+            volScalarField b((2.0/3.0)*tr(D));
+            volScalarField c(2*ck_*delta()*(dev(D) && D));
+
+            return sqr((-b + sqrt(sqr(b) + 4*a*c))/(2*a));
         }
 
         //- Return SGS kinetic energy