  Planetary systems evolve over secular time scales. One of the key mechanisms
that drive this evolution is tidal dissipation. Submitted to tides, stellar and
planetary fluid layers do not behave like rocky ones. Indeed, they are the
place of resonant gravito-inertial waves. Therefore, tidal dissipation in fluid
bodies strongly depends on the excitation frequency while this dependence is
smooth in solid ones. Thus, the impact of the internal structure of celestial
bodies must be taken into account when studying tidal dynamics. The purpose of
this work is to present a local model of tidal gravito-inertial waves allowing
us to quantify analytically the internal dissipation due to viscous friction
and thermal diffusion, and to study the properties of the resonant frequency
spectrum of the dissipated energy. We derive from this model scaling laws
characterizing tidal dissipation as a function of fluid parameters (rotation,
stratification, diffusivities) and discuss them in the context of star-planet
systems.
