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-   -   Need Some doubts to be cleared (https://www.cfd-online.com/Forums/siemens/53725-need-some-doubts-cleared.html)

Arnab March 26, 2004 01:00

Need Some doubts to be cleared
 
Hello All,

I have some doubts regarding my model and in general and I want answers to them and I am sure you guys can help me out.

1. when I do cell check, I get an error saying - "cell faces with very small surface areas found in model" . what is the meaning of this error and can in what circumstances can we neglect this error?

2. Under Lists-Boundaries-Bset = shows list of all the boundaries in set. but what does this sign " * " at the left side mean? some have this sign with it and some dont? can u clear me on that?

3.IMP one :: I have given a model which has combustion in it to work upon. it has got propane, air and other gases in it and chemical scheme is also defined. Now I want to convert this to non combustion model , just to see the flow or air in the model. How can I do it? is it sufficient if I just dont give any chemical scheme number ie , I will not define any chemical scheme. I will leave rest same. Is it alright? I dont think there is any change needed in Thermophysical model and properties.

When I do this and run the model, I get this warning : "No materials are associated with chemical reaction scheme. The scheme will not be written to the problem file. use the chscheme command to associate materials with scheme".

is it ok?? give me some light on this.

Will be waiting for your opinions on this.

Thanks in advance,

Arnab

Brian March 26, 2004 08:26

Re: Need Some doubts to be cleared
 
1. when I do cell check, I get an error saying - "cell faces with very small surface areas found in model" . what is the meaning of this error and can in what circumstances can we neglect this error?

You have some cells with very small faces. Could be that you have collapsed cells and haven't VMERGed, or that there is some serious cell distortion. Ignore if you think the cells are OK. But check these cells first if you have convergence problems or funny results.

2. Under Lists-Boundaries-Bset = shows list of all the boundaries in set. but what does this sign " * " at the left side mean? some have this sign with it and some dont? can u clear me on that?

Means they are in your current Boundary Set.

3. Sorry, not my field. But I should think you should just switch off chemical reactions in the first part of StarGUIde.


Arnab March 26, 2004 22:32

Re: Need Some doubts to be cleared
 
Hello Brian,

Thanks for your answer. but I need more opinions and esp for the 3rd problem I asked for. So I would be happy if someone comes up with answers. Also is there any other Star-CD forums where I can post these questions and get some more opinions.

Thanks in advance,

Arnab

kevin March 29, 2004 18:35

Re: Need Some doubts to be cleared
 
how about just calling up user support?


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