[oozcan]

Hi all,

Is there any knowledge or experience you have ?

Is it possible to affect results?

Does URF decrease solution?

Kind Regards,

[Kushal Puri]

Originally Posted by oozcan

Hi all,

Is there any knowledge or experience you have ?

Is it possible to affect results?

Does URF decrease solution?

Kind Regards,

Decreasing URF so much is not a good solution for damping the fluctuation. You can reduce URF, but not so much because as you reduce the URF much your residual will automatically start decreasing, this is what URF for, but then it will not tell you the exact convergence.

[oozcan]

So, what is the reason of residual oscillations in steady-state ?

[Kushal Puri]

Originally Posted by oozcan

So, what is the reason of residual oscillations in steady-state ?

It depend on the physics of the flow, swirl in the flow, reverse flow or some highly skewed cells may be the reason. Its not always that your residual has to be go down if you are getting periodicity in the fluctuations at some e-03 then you can make a judgement of the convergence from the other parameters, like mass imbalance, heat imbalance etc.

[Antanas]

Originally Posted by oozcan

So, what is the reason of residual oscillations in steady-state ?

It can be transient behavior and/or incorrect integration step size.

[oozcan]

I was solving model in steady-state

[Antanas]

Originally Posted by oozcan

I was solving model in steady-state

That doesn't mean that you flow is absolutely steady (if at all). Still there may be transients which you resolve. So when you solving it in steady-state, residuals may stuck in regular oscillations. Therefore you should also monitor parameters of interest and if they become steady, then it's your solution. Or switch to transient solver.