ENH: Adding kMin to k in dTilda function as dTilda can not be zero in case k = 0

src/TurbulenceModels/turbulenceModels/DES/kOmegaSSTDES/kOmegaSSTDES.C

@@ -62,7 +62,12 @@ tmp<volScalarField> kOmegaSSTDES<BasicTurbulenceModel>::dTilda
     const volScalarField& k = this->k_;
     const volScalarField& omega = this->omega_;
 
-    return min(CDES*this->delta(), sqrt(k)/(this->betaStar_*omega));
+    return
+        min
+        (
+            CDES*this->delta(),
+            sqrt(k + this->kMin_)/(this->betaStar_*omega)
+        );
 }