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-   -   [ANSYS Meshing] ANSYS Meshing hangs at "Preparing to model boundary for part" (https://www.cfd-online.com/Forums/ansys-meshing/92866-ansys-meshing-hangs-preparing-model-boundary-part.html)

jonny_b September 27, 2011 14:08

ANSYS Meshing hangs at "Preparing to model boundary for part"
 
Depending on the model and the types of mesh controls I have, I've noticed that ANSYS meshing can get hung up in the "Preparing to model boundary for part" process. I noticed that the length of time that Meshing spends during this process can be quite variable and I have not been able to pinpoint exactly what causes delays.

I've had to wait for sometimes over an hour before the Mesher moves forward. I've noticed that some information is output to the console during this process and it seems that ANSYS Meshing gets up during this particular event:

Constructing BGrid for the current proximity SF.
... constructing a search tree
... attaching a bgrid
... computing proximity


Does anybody know what exactly is happening during this phase and if there is a way to speed it up.

Thanks,
Jonathan

jonny_b September 28, 2011 12:38

So after doing some testing it appears that any time you make an update to the geometry and then update that geometry information in ANSYS Meshing. The meshing process seems to "reset" itself or something of that sort.

Does someone know if ANSYS Meshing stores some type of information that helps the "preparing to model boundary for part" phase go faster upon subsequent meshing calls?

I hope all of this makes sense. I'm not sure if I'm doing a good job explaining the issue.

jonny_b September 29, 2011 13:42

1 Attachment(s)
To hopefully help clarify the issue I am having, I have attached a screenshot showing the message output that ANSYS Meshing shows in a dialog box and output to the console. The message dialog only says "preparing to model boundary for part", but more information is output to the console during this operation. It appears that a Bgrid (whatever that is) is being created for the proximity SF (whatever that is also!) then it trys to compute the proximity but gets hung up. I wait for over an hour before finally stopping. In the past when I used to mesh the exact same part, it would breeze right through this process and finish the entire mesh in under 10 mins. Again, I made changes to the other parts in the geometry but not to the part that I am trying to currently mesh. Also, I checked and the mesh controls are identical as before.

Anyway, if anybody can provide any guidance what-so-ever I would greatly appreciate it. This issue is driving me nuts because I don't know what ANSYS Meshing is having trouble with so I have no idea about how to fix the problem. If I had one suggestion it would be to provide more information to the user about processes, issues, and errors. To the user. This has always been a gripe of mine about ANSYS Meshing.

jonny_b October 4, 2011 17:26

1 Attachment(s)
I have attached a screenshot showing an error I get when I import the geometry as a parasolid. The error states "face-face inconsistency" could this be the reason why the mesher is taking so long for this geometry?

Does anybody know how to repair this?

Thanks,
Jonathan

coolmech24 January 28, 2012 11:24

i an doing air flow analysis of turbine ventilator n i am also getting similar kind of face-face inconsistency error

Hybrid January 28, 2012 13:50

I experienced the hang-up situation so many times. whenever I use both curvature and proximity based refinement/size, Ansys Meshing hangs. If I use only curvature it works fine.

I suggest try with Curvature only option, ur problem may be solved.

coolmech24 January 29, 2012 02:59

face-face inconsistency
 
thanks for ur suggestion but error is there in design modeller i.e when i import the geometry. so i cannot resolve it in meshing as meshing will not start unless i resolve this error

info_bahaider January 29, 2012 04:37

you didn't mention the "error". will you please?

I usually face this problem during mesh generation with curvature+proximity option ON.

coolmech24 January 29, 2012 05:03

face-face inconsistency
 
i have created the model of turbine ventilator using proe and saved it as .iges. now when i import this geometry in design modeler in ansys at few of the faces i get face-face inconsistency error and so the model is not validated, i cant do meshing unless i validate the model in design modeler.

coolmech24 January 29, 2012 14:33

face-face inconsistency
 
1 Attachment(s)
i have created the model of turbine ventilator using proe and saved it as .iges. now when i import this geometry in design modeler in ansys at few of the faces i get face-face inconsistency error and so the model is not validated, i cant do meshing unless i validate the model in design modeler.[ATTACH]Attachment 11024

coolmech24 February 2, 2012 04:40

finally i have solved my face face inconsistency problem. it arises due to miss match of tolerance value of modeling software and analysis software.i had modeled my part i.e. turbine ventilator in Proe and analysed in Ansys. default tolerance in Proe is .012 mm and that in ansys is .001 mm so i changed tolerance in proe to .0001 mm and the problem is resolved

a_run_91 June 11, 2012 17:15

Quote:

Originally Posted by coolmech24 (Post 342416)
finally i have solved my face face inconsistency problem. it arises due to miss match of tolerance value of modeling software and analysis software.i had modeled my part i.e. turbine ventilator in Proe and analysed in Ansys. default tolerance in Proe is .012 mm and that in ansys is .001 mm so i changed tolerance in proe to .0001 mm and the problem is resolved

http://img502.imageshack.us/img502/5...cosistancy.png

Uploaded with ImageShack.us

I am facing a similar problem in external flow over a car . could you please tell me how can i change tolerance value in ANSYS v13? nothing is mentioned about tolerance in details view of import

I am importing a solidworks model, so can anyone tell me how to change the default tolerance in SW as in proE ??

coolmech24 June 12, 2012 01:55

change tolerance in solidworks and ansys
 
Solidworks

The Dimension Tolerance dialog box is accessible by clicking Tolerance in Tools, Options, Document Properties, Dimensions Options.

Ansys

Tolerance can be changed while meshing the component, there is option to do so in meshing dialog box .


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