Bug in DM
 

I am working on some youtube tutorials where I want to make the Hexa meshing in ICEM on the gambit meshing tutorial (know as sedan tutorial). I wanted to make the some repairing work in DM on sedan , but I am surprised to see that DM is making more issues, whereas Gambit is perfect. I have also tried in ICEM with no errors.

Any one knows what is the problem with DM?

Gambit:
http://imageshack.us/a/img31/2301/gambitj.png


Design Modeller:
http://imageshack.us/a/img841/9301/94666674.png


ICEM:
http://imageshack.us/a/img833/9484/icem.png

can you share file ??
let's investigate this together...

Here you go ;)

https://dl.dropbox.com/u/68746918/sedan.igs

See this thread and post #12 (same case in ICEM : tetra + prism)
http://www.cfd-online.com/Forums/ans...d-pl-help.html

did you try other format, personnaly don't like iges....

OK, may be i have a clue.
The default import option in designmodeler includes "stitch surface" as yes
Switching it to no resolves the problem.
https://dl.dropbox.com/u/35161486/sedan.png

that is may be due to designmodeler trying to stitch a complex set of surfaces...

that is the problem. you are good at DM

are you able to repair the dirty geometry in DM? Or we should use the spaceclaim?

i always use DM, i never used spaceclaim...

I mean, can you repair the missing surfaces, sliver faces, short edge and other problems in sedan cad model (I just shared on forum) in DM.

I see more problems as compared to gambit and ICEM in DM

not sure but let's do this... :D

ok, this is what i've done so far:
i removed some very bad surfaces that were merged to the ones next to them

https://dl.dropbox.com/u/35161486/step1.png

i recreated them using edges:
https://dl.dropbox.com/u/35161486/step2.png

I did a "sew" with a very small tolerance (10e-6 if project was imported in meter)

https://dl.dropbox.com/u/35161486/step3.png

https://dl.dropbox.com/u/35161486/step4.png

Did the same for the back, noticed that surface is not really what i want, but i think that can i be solved if i used a split and did it in two step instead of one:
https://dl.dropbox.com/u/35161486/step5.png

Last surfce is created so i can perform a fill... of course sew has to be done in each steps

https://dl.dropbox.com/u/35161486/step6.png

there may be a easier way of doing this... hope i can discover it in the future when dealing with other geometries

i did the split i mentioned for the back, created three surfaces seperatly then sew:

https://dl.dropbox.com/u/35161486/step7.png

Geometry is repaired:

https://dl.dropbox.com/u/35161486/step8.png

Questions
 

Two questions come into mind:

1. Why in first palce DM had the errors, when gambit and ICEM didn't

2. After repairing are you sure that they are original surfaces?

i don't know how gambit works... because your iges contains surfaces, and since icem cfd is a surface based mesher, it didn't find any difficulty dealing with. DM includes solid and surface, you gave it a hard time maybe ?!
After repairing , the original surfaces are merged and sewed into a new one.
sorry for not being clear here it's first and only things it came to my mind

Gambit is solid direct modeller and works on solid as DM. And that IGES was a solid model and ICEM converted it into surfaces by default.

If that model was not solid then DM would have the surfaces only.

sorry, my knowledge is limited :o

that being said, how about the step file ??

Gambit only provided the IGES file :mad:, but may be I can export that file in step format form gambit and then we try in DM? What do you say?

export step from icem and it will work on DM...