You need to define the respective zone as "dynamic" where you want simulate mesh motion. However you would possibly require a CG motion udf. You can then use the layering method with input of the cell height to simulate mesh motion,

I did it Mr.Mitra. but the problem is that the layering method have limitation in using multiple zone. as the Ansys Help wrote:

http://www.arc.vt.edu/ansys_help/flu_ug/flu_ug_dynam_mesh_update.html#g_flu_ug_face_side

my problem is that how can I separate those cells that are involved in the dynamic layering and use the sliding interfaces capability in ANSYS FLUENT to transition from the deforming cells to the adjacent non-deforming cells

This file should be useful for you. Good luck.

Convert the walls that are common to the upper mesh zone and the lower mesh zone to interfaces. This is how it worked in the CFD s/w I used. Name them in the meshing section and in boundary conditions you can convert them into interfaces. Let me know if u did it already.

Mr.Sravan

thank you for your answer .can you please explain more about your idea?

You mean I should do like as I shown in the picture was attached?(I added them with green color)

Yes Majid. This is what I suggested. There will be 3 interfaces finally - one longer, 2 shorter ones on either side of the small mesh zones. If you have modeled it and set the volume conditions properly in the preprocessing, the train is a solid - so the top segment of the train would be a wall. By doing this you would achieve fluid solid interface (FSI). The interface would elongate with layering option. All the best.

Thank you Durga .I'll do it soon and tell you the result .I hope it works.I added the the image for your confirmation

I added the BSs and Zone types

perfect.

Hi Durga

My preprocessing stages is here

1-I made Faces 1 , 2 , 3 and4

2-I disconnected the edges 1 , 2 and 3

3-I added the BCs as I shown

4-I create solid and fluid zones.

when I import the mesh file to Ansys fluent 15 the fluent removes the boundary condition of wall which was adjacent to the interface(roof of train)

I set the Dynamic mesh settings :

stationary zone as Stationary

Layering zone 1 and 2 as deforming (uncheck smoothing and remeshing )

walls of train (front and back) as rigid body with UDF of motion

the layering was not happened

what is your idea?

I think that I have problem in Gambit mesh generation!

When you mentioned fluid and solid in ansys modeler, the line common to solid and fluid is taken by default as wall. The line common to fluid and fluid is taken as interior or interface. I do not have ansys on my pc. I could have tried otherwise. I hope it is a quad mesh that you have done. If it doesn't work, I suggest that you remove the solid zone. 

Hi durga again

when I import the mesh file to ANSYS fluent it takes the boundaries which above the train as wall .I'm sure that I have problem in pre processing in Gambit.did you have the similar project which has this kind of set up?

I'll send you my whole preprocessing stages in word file I hope you can find my problem,what is you idea?

thanks

Hey Majid,

There might not be any problem with Gambit meshing or probably we could check that later but go through the tutorial for changing boundary conditions. convert the wall into interface as shown in the 7-20 page of the tutorial. You should set interfaces also after this. This should work otherwise send as screenshot of ur mesh in fluent. This ensures that there is information flow from fluid to fluid but not from fluid to solid or viceversa. 

Thanks Durga

I got significant progress the front and back wall of train did layering very good but the main problem is the upper wall of train the Fluent removes it and only the edges which refers to the stationary zone above the train remains.I should remind it I didn't mesh the train because it's useless and I want to know the aerodynamic changes in tunnel.

what is your Idea about it?

best regards

Keep running the mesh movement till the last time step. If it runs fine, you could proceed to setting up initial values and solving for the state variables. 

Hi Mr Zarif

my difficult is wall move to x & y in dynamic mesh .can you help me????

Image url my problem:

http://s7.picofile.com/file/8240748726/udf.zip.html

Hi dear Najid,

I am sorry for taking your time, I just have a quick question, can you finally set up the Fluent for solving such a question? I have exactly the same problem, Can you please help me regarding that?

I highly appreciate your help in advance.