shear stress on a surface
 

hello everyone,
i have a simple 2D problem (i attach a picture of the problem).
left side is velocity-inlet and the right side is pressure-outlet. circle has a constant temperature and the fluid is only water. i want to add hydrophobic boundary condition to the wall(circle) then compare the shear stress on it with the hydrophilic one.
how can i add this boundary condition in fluent?? pls help.

I don't think hydrophobic/hydrophilic properties matter with single phase flow, do they? That has to due with multiphase, droplets and contact angles of those droplets I believe. If the entire volume is flooded with a single fluid, then there are no contact angles, the entire surface is covered.