how to calculate courant number
 

i want to verify that my conditions for my simulation is correct. I am using the courant number equation deltaT/Deltax *v. What option in the mesh controls would you be able to tell the size of deltax?

That number will vary over the mesh. You need to look at the region you're interested in the mesh and determine what value to use.

Alternatively the convective courant number field function will compute the CFL on every cell independently.