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-   -   [ICEM] Geometry clean up (http://www.cfd-online.com/Forums/ansys-meshing/107465-geometry-clean-up.html)

vmlxb6 September 27, 2012 14:14

Geometry clean up
 
Hello everyone,

I have been using ICEM for some time now and I have liked it a lot. I have mostly used it for simple geometries. I now have a complicated one and I am not sure how to clean up the surfaces that are not required. I have uploaded the pics (see link below)

http://imageshack.us/photo/my-images/525/pic1zz.png/

http://imageshack.us/a/img856/9876/pic2oz.png

Since I am going to perform a fluid flow analysis, I need only the volume of air flow. I have already spent 4 hrs trying to manually delete all unwanted surfaces which is getting very tedious. I would appreciate if there was an alternate or faster way of doing that. Thank you very much.

diamondx September 27, 2012 22:15

i would suggest ansys designmodeler. close all the holes, and do a fill operation so you can extract the inside for cfd analysis

vmlxb6 September 28, 2012 10:09

I know that ANSYS design modeler can do the trick but I do not have it. I was wondering if ICEM could do that.

Thanks for the reply.

PSYMN September 28, 2012 11:11

I agree that DM has easier ways to extract the volume from a clean but complex geometry... But this can still be done pretty quickly (but a lot more interactively) in ICEM CFD...


If you have built topology (which establishes connection between surfaces), you can try the following...

Right click on parts => Create Part

Pic a name like "INTERNAL WALL" or "OUTSIDE SURFACE"

Then select one of those surfaces (you can work to select the ones you want to keep or the junk, I usually do both).

Then hit g on the keyboard (or use the selection toolkit that pops up) and select the option to set the feature angle for flood fill. The default is something like 30 degrees, which is often fine, but you can change it if you like.

Then use either the "l" hotkey or "k" hotkey to flood fill select surfaces adjacent to your initial surface (these options are the tipped over paint cans in the select geometry popup toolbox). Very often, this will select all or most of the inside or outside of your cast model, up to the sharp machined edges...

After you are sure that all the junk is in a junk part, you can delete it... Or vice versa, after you are sure you have selected all the surfaces you want in the new part, you can delete the rest... I usually select some surfaces to put into an "outside" part because it is easiest to get to those parts and get rid of them. When I turn off those parts, I can see what else needs to go into that part... If I see surfaces for the inside part, I select (and flood fill) those and turn that part off so it is out of the way. I may occasionally need to turn a part on again to get my bearings as I work thru the model until it is all sorted out.

I recommend putting bad surfaces into a part rather than deleting right away... It is like having a recycle bin that you can easily restore from later if you want, or easily clear when you are sure you have things separated correctly.

yonchong September 28, 2012 16:16

Is fluid path complicated as well or is it quite smooth?

vmlxb6 October 17, 2012 12:03

yonchong
 
The path of fluid is pretty simple. Not very complicated. I have attached the pic with my post you can have a look at it.

Thanks.

vmlxb6 October 17, 2012 13:29

@ simon
 
Thank you very much. This technique is very helpful.


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