Dear Hamda,

When automatic inflation was turned on, both the fluid and the solid had mesh inflation layers.

In your example image, I don't see any inflation layer on the fluid mesh, while I do see it on the solid mesh. It is more important that the inflation show up on the fluid side of the mesh.  Also, in your image, I see some fluid between the spheres. What is supporting the spheres if they are not touching?  Is that just a simplifying approximation to make the meshing feasible?

I recommend you begin the fluid simulation with the tetrahedral mesh, because you get that very quickly. You could spend a lot of time trying to get a structured mesh, and what will be the benefit? Better to spend your time figuring out how to setup the physics and how to get the solution to converge.

Kind regards,