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

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.

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

where are u max, having trouble in meshing still

what kind of meshing trouble?

i cant mesh the vvolume in HEX, only tet

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.

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

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

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

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

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

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

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

hmm? how should i subtract now?

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

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

Then go and mesh the model you displayed

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

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.

How now? i am lost :'(
http://i.imgur.com/yl0Z5.jpg

go and check face.2606

what do u want me do with it? merge with 2384?

if you read the warnings , it says that face.2606 has less than 3 nodes on its outer edges. And can Gambit has difficulty to mesh this face.
So try to mesh this face with finer resolution (eg: more nodes).
Then, as you are in this area check face.2608 and especially sharp angle at vertex.4198.
Here you will have to merge face.2608 with face 2547
This kind of operations is typical

ok max, i cant even continue with i know nothing. Now i need to know what i have done actually. So, i redo everything again
1) I import my stp file.
2) I unite all the Volume.
3) I create the surrounding volume.
4) I subtract it. and i get the pic below
http://i.imgur.com/9TlFn.png
http://i.imgur.com/IzdnO.png
Now i explain this picture then u grade me is it what i done is correct.
remember that first time i told u that the geometry isnt correct due to the hole? Now maybe i get it, the hole is the solid that i subtract of, which mean i am not going to mesh there, but just what i have subtracted (which is the air and the adjacent surface the air contact to) right?

yep
Just for you information: you gonna mesh a complex geometry, especially for a beginner. So don't give up

Hmm, i have found out that from previous what have i done, i had unite all the volume become 1. Lets assume after i mesh it, i need to define boundary condition. Isn't it very tedious as my boundary condition is very complex too. Is it now i have to define it first?
Here, i have upload another image about my boundary condition.
http://i.imgur.com/hFUik.png

Defining boundary conditions is just picking surfaces.
So you can choose them at the end.
You don't need to define the rest as wall since gambit will automatically do it for you
I am not sure modeling the inlet fan is a good idea for a first try.

huh, but i need that in my project.

Then go and mesh what you have.

Before that, i got few question to ask.
When i import my step file, i done some modification on it, that is, moving the PSU abit lower, so that the hole cannot be seen(i sure this is what i need, as that is the casing part that close the PSU itself. then i unite it as usual, it can unite, but 2 message coming out.
WARN : Problematic geometry reported in volume 1. (volume 1 is the only volume left after i unite)
WARN : There are output entities with badly checking geometry.
why?

No idea since I don't have the model (and I cannot reproduce it)
But this is just warning, so you can continue

ok, now i create a volume(i guess if i create it same size as the largest volume(this case is casing) will make me easier as i dont need to spilt the volume to make the size smaller again right?

I don't understand waht you mean

isnt it now i have to create a volume and subtract with the original volume so i can get fluid that i want to mesh? about the volume i want to create, is it i create it at the same size with the casing?

yes, but not smaller.

i done it. Here d pic,
http://i.imgur.com/Fe0Rp.png
but what is the 4 volume coming out for?

should be isolated "fluid"-volumes, but not direct connected with the main one

wat shud i do with that bro?

delete them