[nyyankeejames]

I have been struggling with this issue for a week or so now and I haven't been able to find anything online that was able to resolve my particular problem. Currently, I've been working on a simulating laminar flow through a pipe with a constant heat flux applied at the walls. I've plugged in all the necessary initial values from the experimental data and have thoroughly checked the mesh I'm using, however every time I run fluent my continuity residual doesn't want to converge. I have tried everything from lowering my under-relaxation factors to switching up my solution scheme and spatial discretization. Is there something else that I'm missing or overlooked?

[KevinZ09]

What do you mean with "doesn't want to converge"? What's the starting value and what's your final value? Residual converge doesn't necessarily mean a lot, so don't base yourself just on that. Look at the final results, are those what you'd expect?

[nyyankeejames]

What I meant by saying that "the continuity residual doesn't want to converge" is that it essentially flat lines at around 3.95*10^-5, but I have convergence set at 10^-6. I have included a screen shot to give you a better idea of what I'm talking about.

Also, can you please clarify what you mean by what my starting value and final value are? Are you referring to my residual values of my reported values?

Thanks

[KevinZ09]

That value is fine. You won't always get 1e-6. Actually, more often than not won't you get such a low continuity residual. Most of my work has residuals of 1e-2 or 1e-3. As I tried saying earlier, the residual value doesn't say much, only how much the solution improved compared to the initial solutions. So base your satisfaction of the results on their agreement with experiments, analytical solutions or other numerical solutions.

As for what I meant with starting and final value, I was asking about initial and final value of the continuity residual. But your plot shows that clearly enough.