Question regarding Fluent's Turbulent Pipe Flow Problem
 

I had used FLUENT to resolve the developing flow in a pipe for a pipe Reynolds number of 10,000 on the following meshes: 100x5, 100x20 with uniform spacing in the radial direction.

How do i compare the exit value with the expected value for fully developed flow (e.g., 1/7th profile or your fine mesh results)???

[IMG]file:///X:/Fluent/pipe2/ps1_files/ps1equation.JPG[/IMG]
This should be either less than 4 (so that you resolve down into the viscous sublayer) or greater than 30 (where wall functions can accurately compensate for the poorly resolved viscous sublayer).

However I got a value between 8 and 12 for the 100x20 mesh.

How do i calculate the value of y1+ for each mesh??And how does it help explain the trends in the agreement that i observe??