CONTINuity convergence in ke TURBulence model
 

:D2-D open channel turbulent boundary layer flow over a roughness element in a rectangular domain (expect for the floor mounted cube); with periodic boundary conditions. free surface is being simulated by symmetry condition (cube H = 4mm = width) (channel depth = .5m) (domain width = 0.06 m) (i'm simulating roughness effects)

i'm simulating in Fluent; using k-e turb model with enhanced wall treatment. after processing I generate y* plot to ensure its less than 5. its incompressible and so i'm doing pressure based solver with no bernoulli eq

textbook flow simulation but i'm not seeing the boundary layer develop as nicely as I'd like to even with convergence criterion of 10e-5 on all residuals and fine mesh grading in the vicinity of the boundary......

Are there any other key issues I might be overlooking? I'm also coupling pressure with velocity using SIMPLE-C to help make continuity converge better but this is still an issue

any suggestions would be HIGHLY appreciated..thankyou:):)