negative volume 2d

April 20, 2006, 12:43

Hi,

I'm meshing a square domain with a hole in the middle. Is 2d and very simple, but when I check the grid in fluent it tells me that I have a negative volume! what can I do?

Thanks

April 21, 2006, 04:29

Is it axysymetric? Because then you must not have a grid with negativ y-cordinates.

April 21, 2006, 05:33

Hi, the best thing is to work only in positive directions for x- and y-axis. In case you want to rotate your square, then your rotation axis has to be the x-axis! Claud

April 21, 2006, 05:42

I had a similar problem. Increase number of nodes and try different meshing scheme.

April 21, 2006, 07:52

This is more common when you have highly curved regions in your domain. In this case you have a circle where the grid may generate the negative volume on it. This can be elimintaed by dividing circle into more no. of segments and then mesh it. You need to try with diffrent grid spacings also.

regards

Rajesh

April 20, 2006, 12:43	negative volume 2d	#1
AJG Guest Posts: n/a	Hi, I'm meshing a square domain with a hole in the middle. Is 2d and very simple, but when I check the grid in fluent it tells me that I have a negative volume! what can I do? Thanks

April 21, 2006, 04:29	Re: negative volume 2d	#2
gernot Guest Posts: n/a	Is it axysymetric? Because then you must not have a grid with negativ y-cordinates.

April 21, 2006, 05:33	Re: negative volume 2d	#3
Claud Guest Posts: n/a	Hi, the best thing is to work only in positive directions for x- and y-axis. In case you want to rotate your square, then your rotation axis has to be the x-axis! Claud

April 21, 2006, 05:42	Re: negative volume 2d	#4
philipov Guest Posts: n/a	I had a similar problem. Increase number of nodes and try different meshing scheme.

April 21, 2006, 07:52	Re: negative volume 2d	#5
Rajesh Guest Posts: n/a	This is more common when you have highly curved regions in your domain. In this case you have a circle where the grid may generate the negative volume on it. This can be elimintaed by dividing circle into more no. of segments and then mesh it. You need to try with diffrent grid spacings also. regards Rajesh

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