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Active Member
gschultz
Posts: 9
Registered: ‎12-13-2011

Unable to mesh model

446 Views, 8 Replies
02-27-2012 01:37 PM

I'm trying to model a 4 way valve and cannot get it to mesh as I keep receiving insufficient RAM errors.  I have made adjustments to the point where the maximum element count is only 168,116 but still cannot get the model to mesh at all, even though I have closed everything except CFD.  Previous experience with similar models resulted in the same challenge, the actual count of elements after meshing can be an order of magnitude larger than the approximate element count in the mesh dialog window.  Even with a mesh of over 2,000,000 elements in a prior study, the mesh form at the main flow gap is poor with only 2 elements across the face (despite the selection of 4 elements across the fluid gap in the advanced section).

 

I tried to attach a support only share file but it was 5.25 Mb and did not upload.  How do I send you the support file if the maximum allowed is so much smaller?  Why did CFD create such a huge support file when this is a new study that I haven't been able to mesh yet?

 

My machine has 6 Mb of RAM which has been sufficient until this particular valve.  I've closed everything else and still cannot get it to run.

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Active Member
gschultz
Posts: 9
Registered: ‎12-13-2011

Re: Unable to mesh model

02-28-2012 05:37 AM in reply to: gschultz

Attached is the x_t file for the valve I tried to run last night.  Although this had an estimate of less than 200,000 elements in the mesh set up window, the mesher (running with a fresh computer restart and no other programs loaded) ended up making 1,244,436 nodes and 3,209,052 elements.  Needless to say, I can't run a study with that many elements.

 

This is an urgent request for help!

 

OK, this site does not allow me to attach an x_t file??  And the list of allowable attachments does not include anything I can upload from my cad program (SolidEdge) either?

 

How can you possibly help me if I cannot send any relevant files?

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Employee
LKania
Posts: 29
Registered: ‎02-28-2012

Re: Unable to mesh model

02-28-2012 06:00 AM in reply to: gschultz

An insufficient RAM error means exactly that. You need more memory!

 

The mesh size estimate provided in the meshing task is exactly that - an estimate. Accuracy suffers with increasing model complexity and the nature of the sizing information specified on the model.

 

The quantity entered into the fluid gap element field essentially defines a length scale based upon the detected proximity. Only in the case where enhancement has been disabled will you see the specified number of elements (+/-). With enhanccement enabled a portion of the gap will be "cannibalized" based on the specified thickness factor with the remainder to be meshed with the original length scale.

 

As to the size of the sharefile, either it contains a mesh and/or your model contains a fair amount of entities. Please contact the support team for instructions as to how your sharefile should be uploaded.

 

Lee

 

 

Lee Kania
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Product Support
apolo.vanderberg
Posts: 297
Registered: ‎08-31-2011

Re: Unable to mesh model

02-28-2012 06:24 AM in reply to: LKania

This has been escalated to a Support case via Subscription Center

 

 

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Active Member
gschultz
Posts: 9
Registered: ‎12-13-2011

Re: Unable to mesh model

02-28-2012 06:30 AM in reply to: LKania

Unfortunately memory is not something one can fix very easily.  Up until now I have not had any studies that generated nearly this many elements despite their general similarity to this one.  I've spent two days simplifying the model (filling irrelevant gaps and eliminating interferences) trying to get the count down but it just keeps getting higher.  Are you suggesting that I need to disable enhancement to get the denser mesh where it would be needed?

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Employee
LKania
Posts: 29
Registered: ‎02-28-2012

Re: Unable to mesh model

02-28-2012 06:38 AM in reply to: gschultz

Anytime proximity comes into play mesh counts are almost certainly to be higher - sometimes significantly so, and enhancement in these regions further adds to the mesh count.

 

I can't suggest disabling enhancement without an understanding of the particulars of your model and simulation goals. Give the SimCFD support staff a moment to review your model. I'm confident they will have recommendations for you.

 

Lee

Lee Kania
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Active Member
gschultz
Posts: 9
Registered: ‎12-13-2011

Re: Unable to mesh model

02-28-2012 06:50 AM in reply to: LKania

Lee,

 

Thanks for input.  I'm not sure how much they can do until there is a way to upload the model information.  I'm certain that the support file has no mesh, as that is the option I selected, yet it still generated a file greater than 5 Mb.  It seems like a support website should have the ability to upload far more than 1.5 Mb, and that it ought to be able to accept a basic x_t file extension.

 

I'm going ahead and trying to mesh without enhancements to see what happens as I don't have much to lose and might learn something.

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Product Support
apolo.vanderberg
Posts: 297
Registered: ‎08-31-2011

Re: Unable to mesh model

02-28-2012 06:52 AM in reply to: gschultz

Gary,

   You should have received an email from me about this issue.

Meshing without Enhancement can be useful at times for Diagnostics but is not something we would typically run with to get a solution.

 

Plaese reply to the email with your attachment.


Based on the number of surfaces within the model and the setup details, support files can be as large as 20MB

 

Apolo

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Active Member
gschultz
Posts: 9
Registered: ‎12-13-2011

Re: Unable to mesh model

02-28-2012 07:53 AM in reply to: apolo.vanderberg

Apolo,

 

I've emailed both the latest x_t and a .cfz file from yesterday (that was created prior to this latest x_t).  Right now I cannot open the study so it must be corrupted.  (The UI will open but I get the "CFdesign 2011 has stopped working"  pop-up).  Yes i am still using 2011 since I was told 2012 did not yet support license borrowing, which I am dependent upon since I work remotely).

 

You state the support files can be up to 20 Mb but I get an error message saying they cannot be greater than 1.5Mb, and x-t is not on the list of acceptable extensions so that gets rejected as well.

 

Gary

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