how to determin the "zone_id" of the wall.

[ztdepztdep]

I am conducting the channel_flow, problem. but i found the force outputed is all zero.
I think it must has something with the ""zone_id": 4,"could you please told me how to set the zone_id for the wall bc

[timofeymukha]

You don't set the zone ids in neko, they are defined by your mesh. We should probably have a utility that somehow visualizes what is where.
How did you generate your mesh?

[ztdepztdep]

You don't set the zone ids in neko, they are defined by your mesh. We should probably have a utility that somehow visualizes what is where. How did you generate your mesh?

I use NEK5000 genbox

[timofeymukha]

OK. Generally for box-meshes the recommendation is to use genmeshbox, the native neko tool. But if your walls are in the x-z planes, then the ids should be 3 and 4 for the two walls.

[timofeymukha]

Actually, what you can do is run the mesh_checker utility on the nmsh file. It will give you something like

Labeled zones:
Zone 3: 324 faces
Zone 4: 324 faces

So here 3 and 4 are the walls.

[ztdepztdep]

Actually, what you can do is run the mesh_checker utility on the nmsh file. It will give you something like

Labeled zones: Zone 3: 324 faces Zone 4: 324 faces

So here 3 and 4 are the walls.

I just tried to change it to 1 , it show non-zero values.