[Users] Boundary conditions on a sphere

Dear all,

I would like to know if there is any way ("hacky" or not) to implement boundary conditions on some variables on a sphere within the computational domain. In other words, if there is a way to impose boundary conditions on some subset of the fields at some finite radial coordinate, smaller than the size of the computational domain, while letting the rest of the fields propagate freely until the boundary of such computational domain. I assume this would be easier with a multipatch system, but solutions for a Cartesian grid would also be ok.

Thank you very much for your attention!

Raimon