CFD Online Discussion Forums

CFD Online Discussion Forums (
-   ANSYS Meshing & Geometry (
-   -   [ICEM] Equal Spacing on all the edges (

Tarantino March 13, 2013 16:54

Equal Spacing on all the edges
Hi !

I work with the geometry which including so many blocks. I want to know how can I define an equal spacing for the whole edges, so ICEM decide how many nodes should assign to have the spacing?
For instance, I have two blocks with two difference edge length. for the first I should assign 20 nodes to achieve spacing 0.1 and for the next I should assign 10 node to have 0.1 spacing. Is it possible that I just assign 0.1 as spacing and not Number of nodes? or is it possible to equalized the spacing in different blocks?
In ICEM Pre-Mesh Parameters > Mesh Parameters ones can set number of the nodes and not spacing.
I try Match Edges, but it is not working for this purpose!

stuart23 March 13, 2013 20:56


ICEM does not work like that. For instance, what spacing would you have if you had parallel edges on one block with different lengths?

If your geometry is purely orthogonal, then the method you described would work, however 99.99% of geometries do not contain purely orthogonal parts, and so specifying the number of nodes is the most reliable way.


PSYMN March 14, 2013 09:15

Actually, what I would do, at least to start, is specify 0.1 on the geometry (Mesh tab => Part size setup or something like that). Then when my blocking topology is mostly laid out, I go to blocking => Premesh Params => Update Sizes... This seeds my blocking based on the sizes. But you would end up with that size being a max size. So the count would be set on the shortest edge and would propagate to all the parallel edges...

Stu is right about that being the way things work...

asal March 15, 2013 10:35

This is great. I have also the same issue, but it is work now!
Is it possible to define a default ratio and spacing 1, spacing 2 for the whole blocks also?

For instance the default ration is 2, but I want to assign 1.2 far all edges. Can I do that?

Also I want to know more about Space Relative, Copy absolute, Linked bunching
as well as Match Edge option. I try Match Edge, but I cannot work with it!

Thanks in advance for your reply.

PSYMN March 15, 2013 10:47

Sure, You can adjust the default bunching ratio.

Look under Settings => Meshing Options => Hexa Meshing Options.

You can't setup a default for the initial spacing because that is much more model sizing and edge length dependent.

As for Copying edge distributions, "relative" means relative to the edge length. Absolute means match the actual initial height measurement.

Linked bunching is tricky until you realize that you just need to select the lower end of each set... Turn on bunching and notice the arrows... For the linked bunching, you want to select the edges at the base of the arrow. This should be well explained in the help.

Matching the end spacing is pretty easy. You select the sorce edge and the target edge(s) and it takes the end spacing from the one and copies it to the others... If you use the automatic method, you can't pick which is the source, so there are some options in there to chose if you keep the smallest, average or largest end spacing...

asal March 15, 2013 13:00

thanks for your reply.
just one more question. Is it possible to know the number of elements before convert the unstruct mesh? after it we can see it in mesh info.

PSYMN March 15, 2013 14:13

Yes, right click on Pre-mesh in the blocking branch of the tree and select "pre-mesh info".

All times are GMT -4. The time now is 09:38.