[Danial1992]

hello dear friends,
I'm going to model a one phase flow, using k-epsilon model. I can't get good convergence as I use low velocity for water inlet (like 0.1 m/s), but as I set high velocity it reaches good convergence(like 5 m/s). what is the problem, what should I do?
Is it a mesh problem?
thanks in advanced

[sina_mech]

I would try these solutions:

- Decrease the turbulent intensity to 2% or even 1% (you should actually calculate it rather than using default number or arbitrary values!)

- Use K-Omega SST with low-Reynolds flow option enabled

However, keep in mind that having a lower Reynolds number, increases the importance of viscous term in Navier-Stokes equation, and leads to a boundary layer with a larger thickness. Saying that, I mean since you're using a turbulence model, you need a good (proper) prism layer in that case.