In a stratified and rotating fluid, internal shear layers are systematically generated when an object oscillates at a frequency between the buoyancy frequency and the vorticity of the fluid. In this talk, I first show that these viscous layers have a generic self-similar structure in the limit of large Reynolds numbers. Then, I consider the reflection of these layers on a boundary. I show that a strong meanflow correction is generated close to the reflection point. I provide its asymptotic structure in the limit of large Reynolds numbers according to the boundary inclination. I finally discuss applications of the results in the context of oceanography (tide) and planetary interiors.