[lalupp]

I need to calculate cell Reynolds number of a particular cell for that
the characteristic length L is taken as cube root of Cell volume (mesh.V)
Also velocity vector
mesh().lookupObject<volVectorField>("U")


To access Nu value (kinematic Viscosity) I tried as follows but giving errors
const volScalarField k_viscosity = turbulence->nu();
double viscosity = k_viscosity[celli];


I am new to openfoam and trying openfoam-12 and NACA0012 verification case using SpalartAllmaras Turbulence model
1) How to access the Nu value
2) or Anywhere in the openfoam, cell Reynolds number is calculated?
Any help is Highly appreciated.