Developer's-corner/Boundary-Conditions.md

@@ -20,11 +20,11 @@ Disk {
 ```
 
 **FargOCA** will then invoke those boundaries condition at predefined place in the code. 
-The computational grid has one ghost layer in the radial and in the vertical direction . When running
+The computational grid has one ghost layer in the radial and in the vertical direction . Periodic conditions are applied in the azimuthal direction. When running
 2D simulations only one boundary condition is required (radial)
-while for the 3D case it is necessary to provide a boundary condition for the colatitude (the layer at the disk surface). 
+while for the 3D case it is necessary to provide a boundary condition also for the colatitude (to be applied to the set of gridcells having $`\phi =`$ Opening and $`\phi =\pi -`$ Opening). 
 When a 3D simulation is done by considering only one disk hemisphere (in case of vertical symmetry) a suited mirror boundary
-at the midplane is automatically used by the code. The vertical boundary condition will be applied at $`\phi =`opening 
+is automatically introduced at disk midplane. The vertical boundary condition will be then  applied only to the gridcells having $`\phi =`$ Opening. 
  The aim of boundary 
 condition is to provide a value for the whole set of hydrodynamical
 quantities into the ghost layers.