ENH: turbulenceFields: update turbulence-intensity expression

src/functionObjects/field/turbulenceFields/turbulenceFieldsTemplates.C

@@ -115,14 +115,15 @@ Foam::functionObjects::turbulenceFields::I
     const Model& model
 ) const
 {
-    // Assume k is available
-    const volScalarField uPrime(sqrt((2.0/3.0)*model.k()));
-    const dimensionedScalar U0("U0", dimVelocity, SMALL);
+    // (P:p. 183)
+    // root-mean-square of velocity fluctuations - isotropic turbulence
+    tmp<volScalarField> uPrime = sqrt((2.0/3.0)*model.k());
+    const dimensionedScalar U0(dimVelocity, SMALL);
 
     return tmp<volScalarField>::New
     (
         "I.tmp",
-        uPrime/max(max(uPrime, mag(model.U())), U0)
+        uPrime/max(mag(model.U()), U0)
     );
 }