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-   -   strange problem with structured mesh (http://www.cfd-online.com/Forums/pointwise/130904-strange-problem-structured-mesh.html)

kanon March 5, 2014 17:55

strange problem with structured mesh
 
2 Attachment(s)
I am a novice in pointwise. I just want to try a structured mesh for a 10*10 rectangle. First I just set the dimension as 81 for each connector and made the structure domain, see figure.1 below. However when I increased the dimension to a higher number such as 91, it didn't work, why? see figure.2.
It is very strange and frustrated. Any help is appreciated.
Attachment 29149

Attachment 29150

sanjay March 6, 2014 00:41

I suggest you to split the connector to half on all four sides and mesh for the four partitions.

cnsidero March 6, 2014 09:45

That is strange. It should not be necessary to split the connectors for such a trivial grid.

I created such a domain but didn't see this problem. Can you attach the grid for me to look at? While you can't upload .pw files, if you change the extension to .zip, you can attach it.

kanon March 6, 2014 09:59

Quote:

Originally Posted by cnsidero (Post 478533)
That is strange. It should not be necessary to split the connectors for such a trivial grid.

I created such a domain but didn't see this problem. Can you attach the grid for me to look at? While you can't upload .pw files, if you change the extension to .zip, you can attach it.

Thank you so much, Chris. Please see the attach.
Attachment 29159

cnsidero March 6, 2014 11:55

The forum didn't link the attachment. Send me a PM and you can arrange to email it to me.

cnsidero March 6, 2014 15:23

1 Attachment(s)
Fangping

I loaded your .pw file into Pointwise and it looks OK (see image). Which version of Pointwise are you using?

kanon March 6, 2014 15:28

Quote:

Originally Posted by cnsidero (Post 478605)
Fangping

I loaded your .pw file into Pointwise and it looks OK (see image). Which version of Pointwise are you using?

It is V17.1R4.

cnsidero March 6, 2014 15:49

That's the version I tested it with (see previous image).

Are you still experiencing this problem? My only suggestion at this point is to select the domain and reinitialize it (button with little blue square with yellow star on the corner).

kanon March 6, 2014 15:51

2 Attachment(s)
Similarly for a very simple extrusion problem. If I set the dimension number less than 90 and extrudes it for 10 steps, it works (figure.1). However once I increases the dimension number over 90, it doesn't work neither (figure.2).:confused:
Attachment 29167

Attachment 29168

cnsidero March 7, 2014 09:12

That's very weird behavior. Do you see the same behavior if you use more than 91 points?

kanon March 7, 2014 09:55

Quote:

Originally Posted by cnsidero (Post 478767)
That's very weird behavior. Do you see the same behavior if you use more than 91 points?

Yes, as long as I use more than 85 points it doesn't work.

cnsidero March 7, 2014 10:39

Can you report to me the model and tolerance values from File>Properties.

If it's not that, I'm leaning towards this being some obscure platform related bug. Which OS are you running? 32 or 64bit?

kanon March 7, 2014 10:53

Quote:

Originally Posted by cnsidero (Post 478788)
Can you report to me the model and tolerance values from File>Properties.

If it's not that, I'm leaning towards this being some obscure platform related bug. Which OS are you running? 32 or 64bit?

model size: 1000.0
node: 0.0001
connector: 0.0001
grid point: 1.0e-7

my OS is 64-bit.
Thanks!

cnsidero March 7, 2014 10:57

I did have one other thought. Can you change the display precision to double (Edit>Preferences, Graphics) and see if you get the same result. I might be a rendering issue.

If that's not it, I'm out of ideas :-/

kanon March 7, 2014 11:56

Quote:

Originally Posted by cnsidero (Post 478799)
I did have one other thought. Can you change the display precision to double (Edit>Preferences, Graphics) and see if you get the same result. I might be a rendering issue.

If that's not it, I'm out of ideas :-/

Oh, it works, thank you so much, Chris!:D you helped me a lot.

cnsidero March 7, 2014 12:41

Phew. Now that I know I am also able to replicate the issue. I'm surprised it was that sensitive.

Perhaps Pointwise can educate us on why that it does this. Strange when the range of floating point values only vary a couple of orders of magnitude. Perhaps you should submit a bug report and have them look at it.


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