[Kappa]

Hey,
I need to compute Reynolds-Numbers in a turbulent flow. Assuming I got a 2D-flow and my domain is divided into squares, my question is how to compute the local Reynold-numbers.

Imagine my domain is 1m x 1m and it is divided into 100x100 squares (each having a length of 1cm). Computing the global Reynolds-number (like in the OpenFOAM-Driven Cavity example) looks as follows: Re_global = rho*1m*U_inlet / nu.
If I want to compute the local Reynolds-number for each square I consider 1cm instead of 1m but the remaining variables (rho,U,nu) stay the same, at least for incompressible flow.

As a result, my local Re is only 1% of the global Re. But actually, it should be the same since the velocity, kinematic viscosity and density is the same in the whole 1m x 1m region.
Can you tell me how to compute the local Reynolds-Number in such a flow so that it is an sufficiently accurate representation of the flow in the square?

Thanks to all