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Search took 0.00 seconds. Search: Posts Made By: CeesH
Forum: FLUENT June 2, 2015, 07:24
Replies: 17
Views: 2,994
Posted By CeesH
Checking converence by the residuals alone is bad...

Checking converence by the residuals alone is bad practice - it only indicates your solution is getting better with respect to the initial guess (or, in case the residuals go up, it's getting worse),...
Forum: FLUENT May 28, 2015, 15:03
Replies: 17
Views: 2,994
Posted By CeesH
but what are your levels of mean velocity...

but what are your levels of mean velocity fluctuation at that value of the residuals?

For a stirred tank, assuming you have rushton turbines, you can make a structured hexagonal mesh. If you have...
Forum: FLUENT May 28, 2015, 07:36
Replies: 17
Views: 2,994
Posted By CeesH
How big are the oscillations you are observing?...

How big are the oscillations you are observing? Are the residuals also 'stable' (that is, oscillating but not going down on average)?

I would take second order upwind for all flow variables,...
Forum: FLUENT May 1, 2015, 12:33
Replies: 17
Views: 2,994
Posted By CeesH
Try 10^-5 and a lot more iterations. My...

Try 10^-5 and a lot more iterations. My experience is that a stirred tank takes 2000 - 15000 iterations to converge, depeniding on mesh quality and so on. Also put on some monitors (mean velocity...
Forum: FLUENT April 29, 2015, 16:30
Replies: 17
Views: 2,994
Posted By CeesH
For the vector plots above (these are steady,...

For the vector plots above (these are steady, single phase right?), how many iterations did you do and what did you base convergence on?

Best,
Cees
Forum: FLUENT April 26, 2015, 06:50
Replies: 17
Views: 2,994
Posted By CeesH
I think that interface definition might be the...

I think that interface definition might be the problem indeed. As long as you do not have any periodic boundary conditions and are not using sliding mesh, you don't need to define any special...
Forum: FLUENT April 22, 2015, 10:17
Replies: 17
Views: 2,994
Posted By CeesH
Ah, you are doing 2-phase? That makes life...

Ah, you are doing 2-phase? That makes life somewhat more difficult.

Could you provide the results (contour plot + mesh) of a single phase simulation, in steady state?

Best,
Cees
Forum: FLUENT April 21, 2015, 09:02
Replies: 17
Views: 2,994
Posted By CeesH
hi, 1) if you check your boundary...

hi,

1) if you check your boundary conditions, are you sure there is an interface between the 2 zones in your tank (and not a wall or so)

2) how many iterations did you do? are you sure the...
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