recommended cell expansion ratio

guy_smiling · October 6, 2010, 15:24

Hi all,

I remember reading somewhere that the recommended cell expansion ratio was between 0.833 and 1.2 from adjacent cells, but I can't seem to find that reference anywhere now. Does anyone know if there is a recommended cell expansion ratio and if there's a good reason for it?

Thanks.

LarsPT · October 12, 2010, 13:15

Maybe I found something. If I use high expansion rates, i.e. high cell aspect ratios and run checkMesh -allGeometry -allTopology, I will get an error message because of small determinant of some cells. A cell determinant of 1 relates to a hexahedral cell whereas a small value relates to an illegal flattened cell. As far is I had a look at this problem the error occurs when the cell determinant is smaller than 1e-03. So one can maybe conclude to a maximal aspect ratio?

Lars

October 6, 2010, 15:24	recommended cell expansion ratio	#1
guy_smiling New Member Join Date: Aug 2010 Posts: 11 Rep Power: 15	Hi all, I remember reading somewhere that the recommended cell expansion ratio was between 0.833 and 1.2 from adjacent cells, but I can't seem to find that reference anywhere now. Does anyone know if there is a recommended cell expansion ratio and if there's a good reason for it? Thanks.

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October 12, 2010, 13:15		#2
LarsPT Member Lars Kiewidt Join Date: Sep 2009 Location: Germany Posts: 54 Rep Power: 16	Maybe I found something. If I use high expansion rates, i.e. high cell aspect ratios and run checkMesh -allGeometry -allTopology, I will get an error message because of small determinant of some cells. A cell determinant of 1 relates to a hexahedral cell whereas a small value relates to an illegal flattened cell. As far is I had a look at this problem the error occurs when the cell determinant is smaller than 1e-03. So one can maybe conclude to a maximal aspect ratio? Lars