Convergence issue with fine grid
 

Hi All,
I am trying to study the flow of a fluid inside a circular duct using FLUENT.

I have meshed the geometry using HEX elements.

I am using K epsilon turbulence model with enhanced wall functions.

I have kept 3 cells below y+ < 5 range for Re = 1,00,000 and the solution converged.

But when I use the same mesh for Re = 50,000, continuity equation is not converging. ie Y <<1

Can any body help me out in this issue.

Regards
Hari