[darkluix88]

Hi at all,
I'm studying the sloshing for cars' tanks, so I want to begin my study (I'm at first steps) creating a simple rectangular tank with a negligible length to resolve the problem in 2-D with fluent14.
Now, I've read and seen a lot of tutorials, but there isn't one that makes an example "step to step" for the beginners, so anyone can help me?

For the mesh I'm using gambit, the lenghts are (for example) 15m x 0.1m x 0.5m [L x D x H]...I've created the brick, but now how can I:
1) increase/decrease the number of cells (the command "interval size" doesn't change anything) e realize the mesh?
2) set the boundary conditions on the faces?
3) export only a 2-D face from the tank for 5/6 fluent solver - bidimensional (ps: I've tried over and over but it returns me an error)?

Sorry for my bad English, but thanks to anyone that can help me

[-mAx-]

1) in Mesh/Edge you have to pick severela edges in the same time, for controling them on the fly.
In your case, you select the 4 edges for length, then apply a element size.
The same for 4 edges (height), and 4 edges (width).
after doing thant, normally, if everything is ok, you only have to pick one edge, and all the 3 others will be automatically selected

2) https://www.sharcnet.ca/Software/Gam...one_bound_type

3)I would create another dbs for that, and delete all what you don't need
But your 2d face has to lie on XY plane >> see Export Mesh (XY)
https://www.sharcnet.ca/Software/Gam...le_export_mesh

Here are the tutorials: https://www.sharcnet.ca/Software/Gam...uide/tgtoc.htm

[darkluix88]

At beginning thanks for the help
I have meshed the geometry, but when I try to export 2-D mesh (XY plane) it returns me an error...why?
I have attempted to position the rectangular tank in +X +Y -Z position (with the down-left vertex in the origin of the axes), but I haven't resolved the problem.

[ghost82]

Maybe reporting the error could help

[darkluix88]

Sorry, I forgot to write the error
It is this one:
Error: A 2d export was requested but the mesh is not planar within the tolerance defined in the default FILE_I0.MESH.EXPORT_2D_TOLERANCE.
All mesh nodes must lie on the XY plane or a parallel plane within tolerance.
Errors were found during export. Export file was not created.

[ghost82]

The description of the error is self explanatory: 2d geometry must lie in the xy plane.

[darkluix88]

Yes but it doesn't make sense, because my brick is a parallelepiped and the face of my interest is that on XY plane...what is the problem?

[ghost82]

The problem is that if you have a parallelepiped you have a 3d geometry, so uncheck the 2d export option before exporting and run a 3d simulation. If you want a 2d geometry then draw, mesh and export a 2d square (in the xy plane).

[darkluix88]

Ahhh...so if I have a more complex geometry and for some reason I want to study the problem only on a surface, it's impossible to export the wanted geometry? I have to make only the surface and export this one? (Ps: thanks for the patience )

[ghost82]

No problem
You can perform a 2d simulation if the 3rd dimension (z) doesn't influence your fluid flow (this means having an infinite depth).
But if you have a complex geometry then you must perform a 3d simulation.

[darkluix88]

Thanks ghost82, I have understood!
Now I have another question concerning the boundary conditions. After created the rectangular 2D tank, I wanna apply an oscillating movement to the left side (edge) of the tank using UDF.
So I have set the WALL condition to left, right and bottom edge (calling in order "movement wall", "side wall" and "bottom wall" to distinguish them), but for the upper edge that represents an "open surface", which condition I have to set?
Because I have read in tutorials that I cannot apply the OUTFLOW condition for VOF problem...essentially the tank is open in upper surface and the fluid can go out the tank if the movement is very strong.

I hope to have explained well the question

[ghost82]

You could try with pressure outlet.