Calculation of Delta_x -mesh refinment

I am trying to do grid study (refining mesh). I am using the incompflowparam class in which the physical length is set to 1 by default and the resolution parameter N can be set. Therefore, delta_x= physical length/N. So deltax for most cases is in order of 0.01 ( for example N=100) but as you know in LB deltax is usually equal to 1. Can anybody clarify it to me?

Best regards