ICEM: Holes in Geometry
 

Greetings

i am quite new to the whole CFX stuff. I first used the search engine but i didnt found a solution, which helped me really.

I am working on a rotation symmetric Geometrie with a lot of solid parts in it. So my generall approach in ICEM is to put every material in its own part with a body so i can define my boundaries and material properties in CFXPRE separately.

My Main problem is:

After constructing the Geometry in ICEM, i want to put a Hexa Mesh in it. i do it via the "Mesh by Parts" option. I define my maximum Size (as a first guess) like this:

If the smallest geometric length in a part is X i use as maximum Size for my Hexa Cores X/10. the mesh i get is quite fine (thats my opinion but i am not experienced)

then i start meshing the surface, which often gives me quite good results. But when i mesh the Volume elements i always get the "You have holes in your geometry" error. I tried to put the Tolerance in the "Mesh --> Global parameters" a little bit down (from 0.0001 to 0.1, my geometry has a max size of 210mm)

Furthermore i checked all my parts, all surfaces etc. i can assure that the geometry is fine, there are no intersecting surfaces etc.

What i also see is : If a surface from Part 1 touches a surface from another part 2, the surface mesh is only put on one of the parts. What criteria influences which part is meshed, or how can i Influence it ?

Sorry for the long text, hopefully some of you can assist me.

Greetings,

Daniel

Re: ICEM: Holes in Geometry
 

Dear Daniel,

Holes in the geometry will be shown when there are gaps in the geometry or when definition of fluid domains is improper or there are 2 body points in the same domain or inappropriate mesh sizes are used.Also do geometry repair initially and see for yellow curves.if there are any gaps it would be shown by the yellow curves.so close them and then proceed.Also see that the definition of body points is proper with no confusion.then you would get a mesh without holes in the geometry. cheers, vamsi & prakash

Re: ICEM: Holes in Geometry
 

thanks for the fast answer first !

i got some yellow curves in my geometry, i will try to fix it (with Stuch/match Edges) and then post if everything is working fine.

thanks so far

Re: ICEM: Holes in Geometry
 

it still doesn't work, a short discription what i did. I fixed all yellow curves (added them to the corresponding surface via the stitch/match edges tool in repair geo). Removed all not necessary curves /Points. But still the same prob.

any other idea ?

Re: ICEM: Holes in Geometry
 

Hi Daniel,

The yellow curve normally show the leakage in the geometry(i mean hole so when there is leakage mesh get out and cfx will mesh the volume element outside also.so unless we close the surface properly the hole message will be coming.)Suppose if you have closed the geometry with the correct surface with no gap then either the surface mesh parameters are the creation of the body points might be the reason.Visualise where ever you have to split the doamin and create so many body points .also if you create 2 body points in the same closed box you will get hole message. cheers vamsi