diff --git a/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.C b/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.C
index 59283ac5..4bfadbd0 100755
--- a/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.C
+++ b/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.C
@@ -66,7 +66,8 @@ IBVoidFraction::IBVoidFraction
     propsDict_(dict.subDict(typeName + "Props")),
     alphaMin_(readScalar(propsDict_.lookup("alphaMin"))),
     alphaLimited_(0),
-    scaleUpVol_(readScalar(propsDict_.lookup("scaleUpVol")))
+    scaleUpVol_(readScalar(propsDict_.lookup("scaleUpVol"))),
+    sqrtThree_(sqrt(3.0))
 {
     Info << "\n\n W A R N I N G - do not use in combination with differentialRegion model!\n\n" << endl;
     maxCellsPerParticle_ = readLabel(propsDict_.lookup("maxCellsPerParticle"));
@@ -128,7 +129,7 @@ void IBVoidFraction::setvoidFraction(double** const& mask,double**& voidfraction
                 }
 
                 scalar centreDist = mag(cellCentrePosition - minPeriodicParticlePos);
-                scalar corona = 0.5 * sqrt(3.0) * pow(particleCloud_.mesh().V()[particleCenterCellID], 1./3.);
+                scalar corona = 0.5 * sqrtThree_ * pow(particleCloud_.mesh().V()[particleCenterCellID], 1./3.);
                 vector coronaPoint = cellCentrePosition;
                 if(centreDist > 0.0)
                   coronaPoint += (cellCentrePosition - minPeriodicParticlePos) * (corona / centreDist);
@@ -318,7 +319,7 @@ void IBVoidFraction::buildLabelHashSet
         scalar centreDist = mag(cellCentrePosition-position);
 
         scalar fc = pointInParticle(index, position, cellCentrePosition);
-        scalar corona = 0.5 * sqrt(3.0) * pow(particleCloud_.mesh().V()[neighbor], 1./3.);
+        scalar corona = 0.5 * sqrtThree_ * pow(particleCloud_.mesh().V()[neighbor], 1./3.);
         vector coronaPoint = cellCentrePosition;
         if (centreDist > 0.0)
             coronaPoint += (cellCentrePosition - position) * (corona / centreDist);
diff --git a/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.H b/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.H
index e2072025..0e430dc9 100755
--- a/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.H
+++ b/src/lagrangian/cfdemParticle/subModels/voidFractionModel/IBVoidFraction/IBVoidFraction.H
@@ -68,6 +68,8 @@ private:
 
         const scalar scaleUpVol_;        //NP scaling radius, keeping volume of particle
 
+        const scalar sqrtThree_;
+
 public:
 
     //- Runtime type information