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Search took 0.00 seconds. Search: Posts Made By: maddalena
Forum: OpenFOAM Running, Solving & CFD October 27, 2011, 07:41
Replies: 55
Views: 20,425
Posted By maddalena
Hello, what is the same problem? unstable...

Hello,
what is the same problem? unstable simulation or flow going on the opposite direction you want to?
What OF version are you using? starting from 2.0.0 there is a new bc to simulate fan...
Forum: OpenFOAM Running, Solving & CFD June 28, 2011, 03:06
Replies: 55
Views: 20,425
Posted By maddalena
Hi Nicolas, of course this will not work: ...

Hi Nicolas,
of course this will not work:

You cannot define something as cyclic and than apply to it a standard BC! Cyclic wants something that requires cyclic, i.e. cyclic or fan. Not something...
Forum: OpenFOAM Running, Solving & CFD October 12, 2010, 09:45
Replies: 55
Views: 20,425
Posted By maddalena
Tried that, without success... :(

Tried that, without success... :(
Forum: OpenFOAM Running, Solving & CFD October 11, 2010, 02:50
Replies: 55
Views: 20,425
Posted By maddalena
Hi Eugene and thank you for your answer. ...

Hi Eugene and thank you for your answer.

Yes, that sounds a logical explanation. But this is a fan indeed!
Already tried that (some posts above, but it is "hidden"). You are right, stability does...
Forum: OpenFOAM Running, Solving & CFD October 8, 2010, 05:26
Replies: 55
Views: 20,425
Posted By maddalena
Hi Eugene, I used a laminar model only on the...

Hi Eugene,
I used a laminar model only on the first 100 time steps, just to help the solver. Then I switched on the turbulence.
My schemes are the following:


gradSchemes faceMDLimited Gauss...
Forum: OpenFOAM Running, Solving & CFD October 7, 2010, 02:41
Replies: 55
Views: 20,425
Posted By maddalena
No way. Simulation crashed after few time steps...

No way. Simulation crashed after few time steps using the zeroGradient condition at the inlet and at the outlet. Ideas?

mad
Forum: OpenFOAM Running, Solving & CFD October 6, 2010, 08:18
Replies: 55
Views: 20,425
Posted By maddalena
Hello, bad news: the following caused velocity...

Hello,
bad news: the following caused velocity instabilities (i guess due to the numerics) close to the fanOutlet,


fanOutlet = domain inlet

U: directMapped, setAverage:...
Forum: OpenFOAM Running, Solving & CFD October 6, 2010, 02:45
Replies: 55
Views: 20,425
Posted By maddalena
Hi Robin, are you using cht? If it is so, I...

Hi Robin,
are you using cht? If it is so,
I think that you can use the fan as an interface coupling, indeed this is what you do when applying the directMapped. Why do not create the two fan faces...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 08:32
Replies: 55
Views: 20,425
Posted By maddalena
Yes, I saw that is not possible to fix the...

Yes, I saw that is not possible to fix the average value when using the directMappedVelocityFluxFixedValue. This means that I cannot fix the mass flux in my case.
I have the first simulation...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 07:47
Replies: 55
Views: 20,425
Posted By maddalena
Ah yes! I should have noticed by myself! :o There...

Ah yes! I should have noticed by myself! :o There is an example among the tutorials...
Just as an information: do you know why the BC condition is directMapped and in the...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 06:08
Replies: 55
Views: 20,425
Posted By maddalena
Stefan, can you comment on this? I am...

Stefan, can you comment on this?

I am getting the following error:
--> FOAM FATAL ERROR:

gradientInternalCoeffs cannot be called for a genericFvPatchField (actual type...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 04:37
Replies: 55
Views: 20,425
Posted By maddalena
One more question: This is my 0/U: ...

One more question:
This is my 0/U:
outletFan
{
type directMappedFixedValue;
value uniform (1.42 0 0);
setAverage true;
average...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 04:31
Replies: 55
Views: 20,425
Posted By maddalena
Ok, perfect, I will try this one. What about the...

Ok, perfect, I will try this one. What about the boundary file? Is this ok?
outletFan
{ type directMappedPatch;
nFaces xx;
startFace xx;
sampleMode ...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 03:58
Replies: 55
Views: 20,425
Posted By maddalena
Or is that the (total) pressure jump that the fan...

Or is that the (total) pressure jump that the fan should assure to have the flow moving? Thus the (total) pressure losses due to the system?
Thus you suggest:


fanOutlet = domain inlet

...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 03:44
Replies: 55
Views: 20,425
Posted By maddalena
Hi Stefan and thanks for joining this thread. ...

Hi Stefan and thanks for joining this thread.
Yes, that is correct.

am I right if I say that the setAverage option used to set the average value of the field, thus velocity in this case? Since I...
Forum: OpenFOAM Running, Solving & CFD October 5, 2010, 02:34
Replies: 55
Views: 20,425
Posted By maddalena
Hi Robin, Thus if I understand right, you...

Hi Robin,

Thus if I understand right, you used an iterative process to check the mass flow. This has been suggested me elsewhere (here...
Forum: OpenFOAM Running, Solving & CFD October 4, 2010, 07:44
Replies: 55
Views: 20,425
Posted By maddalena
Hi Eugene, Well, the simulation was not so...

Hi Eugene,

Well, the simulation was not so stable using zeroGradient, thus I looked at one of the tutorial where the flowRateInletVelocity is used, and it was coupled with a fluxCorrectedVelocity....
Forum: OpenFOAM Running, Solving & CFD October 4, 2010, 03:20
Replies: 55
Views: 20,425
Posted By maddalena
Hi, Just to say I have solved this: and...

Hi,
Just to say I have solved this:

and now pressure has the expected distribution. However, the simulation is not stable and residual never get low. My fvScheme and fvSolution should not be the...
Forum: OpenFOAM Running, Solving & CFD October 1, 2010, 06:00
Replies: 55
Views: 20,425
Posted By maddalena
Question How to model a fan fixing the mass flow rate?

Hi everyone,

searching here and there, but i still miss something... maybe open a new thread will help me a bit.
I would like to model a fan inside a closed loop circuit, fixing the mass flow and...
Showing results 1 to 19 of 19

 
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