Assigned Volume-Numbers 2

[burtek]

Hi,
I need to know the general idea of behind the assigned volume-numbers:

when 3 or 4 new volumes are generated at the same time by Booleans operations, which volume takes which volume-number? Is there an order of precedence?

I need only this general idea. Because depend on this idea I had to write a program whose output txt-file will be used input file of Ansys.

Regards

 

[ansysfreak]

Why use volume number they alway can change, try to do by location or size etc.

Garry

 

[burtek]

Hi Garry,

thanks, but I need to know how change the volume-number. In my program I have to call something depend on the volume-number.

regards

 

[TGS4]

I would consider the assignment of volume numbers to be an essentially random process, that is certainly not repeatable. (I also believe that the ANSYS TFM also infers this). Ansysfreak has it right - do not rely on the numbers! If you ABSOLUTELY MUST have volume numbers, then locate the volume based on its location or size, and the *GET the volume number.

 

[burtek]

Hi TGS4,

thanks, could you please explain, what you mean
"locate the volume based on its location or size " ?

regards

 

[TGS4]

You could use the vsel command, or the lsel, followed by an asll, followed by a vsla, or a asel, followed by a vsla. Check out these commands in TFM.

 

[burtek]

Hi,

I found this information in ANSYS Help File:

"Caution
The numbering of Boolean output entities is not 100% predictable. That is, sometimes the same Boolean operation, when performed on different computer systems, will assign different numbers to output entities. If you plan to generate an input stream file interactively on one machine and rerun that input stream on another system, you should avoid using entity identification numbers in your command stream. Instead, use selecting logic to identify specific entities as needed.
"

regards

 

[Struct71]

How about using the

NUMST,VOLU,XXXX

command where XXXX is a large number which you are sure is not used? New volumes that are generated will be numbered starting at XXXX.

You can get the largest assigned volume number with

*GET,XXXX,VOLU,0,NUM,MAXD


To retrieve volume (and other entity) numbers I sometimes use

VSEL,NONE
[volume generation command]
XXXX=VLNEXT(0)

Hope this helps...

PS: Why use a program to create an ANSYS input file?
Ansys input files are perfect for programming...