[Tariq Ahmed]

Hi,
I am doing a 2D simulation and created a 2D geometry. So I created a geometry as in the figure for a simple case where there is an U tube and hot water flows from one end (top) to the other(top). The tube goes through the rectangular domain(wall) where bulk water is present and exchanges heat with it.

screen.jpg

I tried creating surface for the rectangular domain as one fluid and separated this surface from the pipe/tube curves and created another separate surface for the tube water. I am trying ICEM unstructured meshing since the real case has 16 bends of tubes and I am doing an initial simple case but for this simple case, I am not able to get a working mesh with boundary conditions in Fluent. I have specified all the boundary conditions but i get wall for all the parts i specified.

I have these following parts:

Adiabatic Thermal Wall (Rectangular Domain)
Fluid (Surface for the rectangular domain)
HEX Pipe Wall
Water Inlet
Water Outlet
Tube Fluid (Surface inside the tubes)

I also tried creating 2 bodies one for bulk water (FLUID) and another inside the tube (TUBE FLUID). But in Fluent, it doesn't recognize them as the above and gives the following
zones, wall_hex_pipe:003-shadow
wall_adiabatic_thermal_wall-shadow
wall_hex_pipe-shadow
wall_hex_pipe:004
wall_hex_pipe:003
wall_adiabatic_thermal_wall:002
wall_hex_pipe
wall_adiabatic_thermal_wall
int_hex_pipe
int_adiabatic_thermal_wallSlitting wall zone 16 into a coupled wall.
Error: 1nquire-adjacent-threads: not a face thread


Error: 1nquire-adjacent-threads: not a face thread
Error Object: #f



Skipping zone fluid_outertubefluid (not referenced by grid).
Skipping zone tubefluid (not referenced by grid).
Skipping zone adiabatic_thermal_wall (not referenced by grid).
Skipping zone hex_pipe (not referenced by grid).
Skipping zone water_outlet (not referenced by grid).
Skipping zone int_outertubefluid (not referenced by grid).
Skipping zone int_fluid (not referenced by grid).
Skipping zone outertubefluid (not referenced by grid).
fluid
Skipping zone fluid_outertubefluid (not referenced by grid).
Skipping zone tubefluid (not referenced by grid).
Skipping zone adiabatic_thermal_wall (not referenced by grid).
Skipping zone hex_pipe (not referenced by grid).
Skipping zone water_outlet (not referenced by grid).
Skipping zone int_outertubefluid (not referenced by grid).
Skipping zone int_fluid (not referenced by grid).
Skipping zone outertubefluid (not referenced by grid).
Skipping zone fluid (not referenced by grid).
fluid-11

It would be helpful if you can guide me through where the problem exists.