What does wall-shadow mean?

If a "WALL" is between solid phase and fluid phase geometically, when you import the *.msh file into solver, FLUENT splits the "WALL" into "WALL" and "WALL_shadow". "WALL_shadow" can be adjacent to solid phase or fluid phase.

If you only solve momentum equations, "WALL_shadow" is not important to your solution. However, in case of solving energy equations, "WALL_shadow" part is meaningful.

For example, if "WALL" is adjacent to liquid phase and "WALL_shadow" is adjacent to solid phase in your system, convective heat transfer is considered at the "WALL" side. In contrast, at the "WALL_shadow" side, conduction is considered.

In this way, energy equation solutions are coupled at the interface between solid and fluid by considering two walls.

[Rashmichem]

Hi

I also have the same problem. Iam solving a counter current tube inside a tube simulation. when i export the mesh file into fluent it shows wall is split into wall and wall_shadow. I know the reason for this. But i want to know what should be the BC for wall and wall_shadow.. suppose i want to give heat flux value i have to give the same value on shadow and wall_shadow? but if i couple there is no option to fill in heat flux.. Kindly suggest

Thanks

Rash