[ripong]

I am running k-omega model with low Reynolds number correction using FLUENT. My 3-D geometry looks like a tree with multiple inlets with a single outlet. The Reynolds number at the outlet tube (it is maximum there) is ~13000 and at inlet tubes are ~500.

After running it for thousands of iterations, residuals for mass convergence and xyz velocities reached close to 1e-6 and started fluctuating in that range. But residuals for k and omega values do not decrease less than 1e-5.

My questions are
1. Is it alright to apply more stringent convergence rules for mass and xyz velocities and more lenient for the k and omega values?
2. What are the residual values "generally accepted" for solution convergence for each quantities?
3. I decreased the mesh density and the solution converged better (i.e., residuals reached lower level). Is this alright to trust the coarse mesh solution than the finer one? Both look similar except for small structures appear in the highest velocity domain in the finer mesh solution. I wonder if this is real or an artifact. How should I verify?

Thank you!!