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Sabatini January 22, 2001 04:50

cracks in the model
 
hay i did refinement in my model from 32*32*200 cell of 64*64*200 the programm Satrcd give one error there are cracks in the model how i can make a korrection of this error thanks.

Mathew C. Mathew January 26, 2001 17:17

Re: cracks in the model
 
Hello there,

By saying that there are cracks, I presume that they are from the refinement. To confirm this use the cell check tool which can be found in the Star Guide under 'Check and Fix Grid' in select 'Check Grid' or from the 'Tools' drop down menu then select 'Check tool'.

In both these tools you will find some form of drop down 'Check Option' menu to select 'Crack' (to check for cracks), use the other drop down menus to select 'All' (implies that it will check all cells), and then 'New Set' (implies it will create a net set of the offending cells).

Click 'Apply' and all the cells will be checked for cracks, the cells which constitute to the crack problem will be placed into a new cell set, allowing you to select 'Cell Plot' from the main window, and then visually see the cells causing problems.

My assumption is that the cracks are due to connecting cells NOT sharing the same vertices, due to new cells and vertices being created from the refinement procedure (I have never refined in this manner, so that last statement is a guess). If this is the problem, then the solution is easy :-

Select all the cells (and only the cells) which should be connected, hence share vertices. Then select a new vertex set based on the current cell set. Goto the Star Guide, and select the 'Create and Import Grids' then select 'Assemble Grids'. There will be a tab for vertex merge, and ensuring that you have selected 'Current Vertex Set' select merge.

I recommend that you back up your model first however, and get another opinion about the nature of the cracks from a friend, for comfirmation.

Kind regards Mathew C. Mathew Student Kings College London

Sabatini January 29, 2001 10:29

Re: cracks in the model
 
hallo Marhew,

i have done what you said but with the same error,the probleme i work in the refinement with the spacing factor. thanks for yur suggestion

Joern Beilke January 29, 2001 11:37

Re: cracks in the model
 
you should tell us exactly what you are doing (all the commands you are using for refinement) if you really want some help. Did you do a cpmatch after the refinement?

Sabatini January 30, 2001 07:13

Re: cracks in the model
 
Hay Joern

the problem is so: i have one square duct 25*25*500 mm,in the first time ihave in I direction 16 cell with the spacing factor 0.8 in J direction 200 cell with the spacing cell 1 in k direction 16 cell with the spacing cell 1.2. the problem converge after the refinement i have in I direction 32 cell with the spacing factor 0.8 in J direction 200 cell with the spacing cell 1 in k direction 32 cell with the spacing cell 1.2. in the check the starcd give the 4584 cracks found i the model. thanks.



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