Question about the Reynolds number used to estimate the wall cell width
 

Hi

Here's the formula given in this forum to estimate the wall cell width.

http://www.cfd-online.com/Wiki/Y_plu...nce_estimation

May I ask how is L_boundarylayer defined here?

Is Re calculated here different from the Re we use to estimate the flow regime? (The Re to estimate the flow regime is calculated by characteristic length which could be very different from L_boundarylayer.)

By the way, for laminar flow, shall we still use this formula to estimate the wall cell width? If not, what formula shall we use?

Thank you very much.