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-   -   meshing and boundary condition (https://www.cfd-online.com/Forums/fluent/81495-meshing-boundary-condition.html)

-mAx- January 10, 2011 10:42

First do the tutorial and you will understand some basics.
Then you can work with your project.

no183 January 11, 2011 11:45

i done the tutorial bro. But unfortunately, i need the gambit meshing tutorial? because i still not quite clear with the function, map, cooper etc.

no183 January 16, 2011 00:26

sorry was busy this few day. I got it. Now i know, the purpose i create the block(brick) is used to mesh inside it so that i can mesh the air(space)? just my 2 cents

no183 January 20, 2011 07:57

where are u max, having trouble in meshing still

-mAx- January 20, 2011 07:59

what kind of meshing trouble?

no183 January 20, 2011 08:40

i cant mesh the vvolume in HEX, only tet

-mAx- January 20, 2011 08:51

You have a complex geometry, forget trying to mesh it with hexa on the fly. You will need many volume decomposition and patience for achieving it.
Even with tetra, you will need to decompose your volume (but less than with hexa) and it won't be easy at all to get a good tetra mesh (skewness < 0.9)
I would try to mesh it first with tetra, and use Hexcore scheme: it will fill your domain with hexa.

no183 January 20, 2011 08:53

Ya my skewness >0.97.. can i send u my dbs for verification?

-mAx- January 20, 2011 09:08

spoload your dbs on a sharre server I will check it tomorrow.
In examine Mesh, set the lower skewness to 0.9 (instead of 0) and Update:you will see where are all the cells with skewness above 0.9.
Then check if you don t have small edges, small angles, or any topology issue in those areas

no183 January 20, 2011 09:16

i have save in in dbs and zip it.. will upload it later tonight.

no183 January 20, 2011 11:17

http://rapidshare.com/files/44359048...shing_done.zip
i have upload it, kindly help me check, thanks !

-mAx- January 21, 2011 01:14

your geometry isn't ready for meshing:
*delete volume.5
*copy face.3048 with (0 0 -160.5) --> new face.3049
*split volume.2 with face.3049 --> new volume.7
*delete volume.7
*copy face.3043 with (0 0 149) --> new face.3052
*split volume.2 with face.3052 --> new volume.7
*delete volume.7
*copy face.3056 with (-35 0 0) --> new face.3057
*split volume.2 with face.3057 --> new volume.7
*delete volume.7
*copy face.3055 with (0 35 0) --> new face.3084
*split volume.2 with face.3084 --> new volume.7
*delete volume.7
*copy face.3087 with (35 0 0) --> new face.3089
*split volume.2 with face.3089 --> new volume.7 and volume.8
*delete volume.8, volume.3, volume.4, volume.6
Now your geometry is ready for meshing, but it will fail because of topology, especially in fans area (just read where gambit failed to mesh surfaces, and fix)
NB: the generated id's from entity could differ from OS, so check id's in the transcript window

no183 January 21, 2011 08:27

Bro, i have done what u ask, unfortunately, i dont know what is going wrong, some how, i still got error
http://imgur.com/ks1aq

-mAx- January 21, 2011 08:38

there are not errors: hollow parts are your solid parts, which are not in interest since you don't want solid conduction.
You have substracted them.
Now you have fluid domain.
Same theme here:http://www.cfd-online.com/Forums/ans...g-help-me.html

no183 January 21, 2011 08:42

hmm? how should i subtract now?

-mAx- January 21, 2011 08:48

why do you want to mesh those parts?
do you want to compute solid conduction in solid elements?

no183 January 21, 2011 08:52

nope, my scope is convection only. So i will do the convection part first.

-mAx- January 21, 2011 08:56

Then go and mesh the model you displayed

no183 January 21, 2011 08:57

hmm, as easy as "mesh volume" select volume 7?

-mAx- January 21, 2011 09:01

yes.
It will fail, but it will give you some informations, where it failed to mesh. (--> transcript window)
Then try to understand why.
Typically, you will have small edges or small angles.
And you can fix them by merging surfaces together.


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