From 57d7158fa960a4538c8a223238b7feb613783ce1 Mon Sep 17 00:00:00 2001
From: andy <a.heather@opencfd.co.uk>
Date: Mon, 8 Dec 2008 17:01:59 +0000
Subject: [PATCH] added calcInterval - defaults to 1 if not present to
 recapture earlier behaviour

---
 .../LES/vanDriestDelta/vanDriestDelta.C              | 12 ++++++++++--
 .../LES/vanDriestDelta/vanDriestDelta.H              |  1 +
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.C b/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.C
index da55d3518b..0979890dbf 100644
--- a/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.C
+++ b/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.C
@@ -115,6 +115,10 @@ vanDriestDelta::vanDriestDelta
     Cdelta_
     (
         dd.subDict(type() + "Coeffs").lookupOrDefault<scalar>("Cdelta", 0.158)
+    ),
+    calcInterval_
+    (
+        dd.subDict(type() + "Coeffs").lookupOrDefault<label>("calcInterval", 1)
     )
 {
     delta_ = geometricDelta_();
@@ -131,14 +135,18 @@ void vanDriestDelta::read(const dictionary& d)
     d.readIfPresent<scalar>("kappa", kappa_);
     dd.readIfPresent<scalar>("Aplus", Aplus_);
     dd.readIfPresent<scalar>("Cdelta", Cdelta_);
+    dd.readIfPresent<label>("calcInterval", calcInterval_);
     calcDelta();
 }
 
 
 void vanDriestDelta::correct()
 {
-    geometricDelta_().correct();
-    calcDelta();
+    if (mesh().time().timeIndex() % calcInterval_ == 0)
+    {
+        geometricDelta_().correct();
+        calcDelta();
+    }
 }
 
 
diff --git a/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.H b/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.H
index 66fe691c10..854fa181bb 100644
--- a/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.H
+++ b/src/turbulenceModels/incompressible/LES/vanDriestDelta/vanDriestDelta.H
@@ -61,6 +61,7 @@ class vanDriestDelta
         scalar kappa_;
         scalar Aplus_;
         scalar Cdelta_;
+        label calcInterval_;
 
 
     // Private Member Functions