External Radiation Boundary Condition (Two sided wall), Grid Interface
 

I am solving a transient aerothermal problem.
A simple blunt cone is travelling at supersonic speed.
I want to include Radiation heat transfer from body to fluid (air).
If I use radiation option in thermal boundary condition (at wall) then is it ok or not?

I am using grid interface between blunt cone surface and fluid. When I create interface, fluent automatically generate four walls, namely:

1. Boundary Zone 1
2. Boundary Zone 2
3. Interface Wall Zone 1
4. Interface Wall Zone 2

For Interface Wall Zone 1 and Interface Wall Zone 2 fluent automatically assign coupled boundary condition (thermal boundary condition).
For Boundary Zone 1 and Boundary Zone 2 fluent automatically assign heat flux = 0 boundary condition (thermal boundary condition).
These boundary conditions for all four walls are ok or we need to modify it?

If I want to use External Radiation Boundary Condition (Radiation heat transfer from body to fluid), in which wall I should use Radiation boundary condition?

Thanks and Regards