I am developing my own code to do some simple computation, and i wanna read the *.msh file generated by Gambit. However, i have no idea of the file format. Could anybody here give me a hand? Any help will be appreciated.

create a simple rectangular 2-d geometry and make just few grid points. open the .msh file with wordpad and look at it.

-H

fluent's manual describe the mesh format in section cas and data file formats (in the cas section you will have all the details you need).

To get the basic grid informations select "generic" as solver type and export the neutral grid *.neu. Neutral mesh files are easy to unterstand even without the manual. they are devided into 3 sections: 1. a header with basic grid informations (number of nodes, number of elements,...); 2. the point coordinates and 3. the elements (wich points form a an element). if you added boundaries in gambit there will be an 4th section with boundary informations.

good luck rom

actually i did it just as you suggested, but i failed to get the exact meaning of the file. it's a little bit troublesome.

the following is an example: a cavity with each edge divided into four parts, that is , nine cells.

(0 "GAMBIT to Fluent File")

(0 "Dimension:") (2 2)

(10 (0 1 10 1 2)) (10 (1 1 10 1 2)(

0.0000000000e+000 1.0000000000e+000

1.0000000000e+000 1.0000000000e+000

0.0000000000e+000 0.0000000000e+000

1.0000000000e+000 0.0000000000e+000

1.0000000000e+000 3.3333333333e-001

1.0000000000e+000 6.6666666667e-001

0.0000000000e+000 6.6666666667e-001

0.0000000000e+000 3.3333333333e-001

3.3333333333e-001 1.0000000000e+000

6.6666666667e-001 1.0000000000e+000

3.3333333333e-001 0.0000000000e+000

6.6666666667e-001 0.0000000000e+000

6.6666666667e-001 3.3333333333e-001

6.6666666667e-001 6.6666666667e-001

3.3333333333e-001 3.3333333333e-001

3.3333333333e-001 6.6666666667e-001 ))

(0 "Faces:") (13(0 1 18 0)) (13(3 1 9 3 0)( 2 1 7 9 0 2 7 8 6 0 2 8 3 3 0 2 3 b 3 0 2 b c 2 0 2 c 4 1 0 2 4 5 1 0 2 5 6 4 0 2 6 2 7 0 )) (13(4 a c 14 0)( 2 1 9 0 9 2 9 a 0 8 2 a 2 0 7 )) (13(6 d 18 2 0)( 2 d c 1 2 2 5 d 1 4 2 f b 2 3 2 d f 2 5 2 f 8 3 6 2 e d 4 5 2 6 e 4 7 2 10 f 5 6 2 e 10 5 8 2 10 7 6 9 2 a e 7 8 2 9 10 8 9 ))

(0 "Cells:") (12 (0 1 9 0)) (12 (2 1 9 1 3))

(0 "Zones:") (45 (2 fluid fluid)()) (45 (3 wall new_wall.4)()) (45 (4 mass-flow-inlet wall.4)()) (45 (6 interior default-interior)())

i think i will try more to find it in the manual. thank you !

compared to the *.msh, the *.neu file is easier to understand. But the problem is that some boundary conditions such as "wall","mass flow inlet", are not compatible with this filetype, so i cannot add the BC to the *.neu file, which make me turn to *.msh file.

[jntan]

The structure of *.msh file is closely related to FLUENT solver. Although you can easily open the file with a wordpad something and extract the point information, only point information is far from enough to be utilized in a solver. You need more information on how these points are connected and how the volume cells are built.

I spent more than 1 year looking into the *.msh file structure and finally figured it out. Then I built my own solver for research purpose on that. Drop me a message if you are interested in more details.

cheers,

[Okke79]

Dear jntan,
I am very interested in more details about reading the *.msh file.
Regards,
Okke

[znri]

Originally Posted by jntan

The structure of *.msh file is closely related to FLUENT solver. Although you can easily open the file with a wordpad something and extract the point information, only point information is far from enough to be utilized in a solver. You need more information on how these points are connected and how the volume cells are built.

I spent more than 1 year looking into the *.msh file structure and finally figured it out. Then I built my own solver for research purpose on that. Drop me a message if you are interested in more details.

cheers,

Hi,
I need to edit my msh file manually. Can you please tell me how can I start to find the structure of fluent msh files?
Best regards