How to set up meshes of sparse and small holes?

leeyee · August 5, 2010, 22:57

Hi guys,

I have a problem when trying to model sparse holes in a cylinder. Our model is quite simple, it's just several holes in a solid cylinder. However, these holes are sparse and quite small compared to the radius of the cylinder. Specifically, it's just 3um radius for holes but the cylinder is 310um! So here comes the problem, I don't how to set up meshes to resolve such small holes but still remain consistency of cells so that Flow-3D can calculate. Otherwise I have to set up a dense mesh, but in that case Flow-3D is unacceptable slow and wasting most of the time calculate unneeded cells, because fluid only appears in holes, theoretically we don't need to calculate solid part. Can anyone help out?

Thanks sincerely.

MuxaB · September 2, 2010, 22:50

If there is no heat transfer, then cells inside blocked areas are automatically deactivated and removed both memory and calculation, leaving only the open cells active, so it would be ok to mesh the whole cylinder finely. Alternatively, you could use multiple mesh blocks concentrated around the holes, leaving the rest of the cylinder either unmeshed or mesh with a coarse mesh block.

August 5, 2010, 22:57	How to set up meshes of sparse and small holes?	#1
leeyee New Member Ye Li Join Date: Jul 2010 Posts: 5 Rep Power: 15	Hi guys, I have a problem when trying to model sparse holes in a cylinder. Our model is quite simple, it's just several holes in a solid cylinder. However, these holes are sparse and quite small compared to the radius of the cylinder. Specifically, it's just 3um radius for holes but the cylinder is 310um! So here comes the problem, I don't how to set up meshes to resolve such small holes but still remain consistency of cells so that Flow-3D can calculate. Otherwise I have to set up a dense mesh, but in that case Flow-3D is unacceptable slow and wasting most of the time calculate unneeded cells, because fluid only appears in holes, theoretically we don't need to calculate solid part. Can anyone help out? Thanks sincerely.

September 2, 2010, 22:50		#2
MuxaB Senior Member michael barkhudarov Join Date: Mar 2009 Location: Sante Fe, New Mexico, USA Posts: 336 Rep Power: 18	If there is no heat transfer, then cells inside blocked areas are automatically deactivated and removed both memory and calculation, leaving only the open cells active, so it would be ok to mesh the whole cylinder finely. Alternatively, you could use multiple mesh blocks concentrated around the holes, leaving the rest of the cylinder either unmeshed or mesh with a coarse mesh block.