Nonlinear simulations of tides in the convective envelopes of low-mass stars and giant gaseous planets

TL;DR

This paper uses 3D nonlinear simulations to explore how nonlinear effects influence tidal flows, energy, and angular momentum dissipation in the convective envelopes of low-mass stars and giant planets, revealing the impact on their evolution.

Contribution

It introduces a novel simulation approach to study nonlinear tidal interactions, highlighting their role in angular momentum transfer and dissipation in stellar and planetary envelopes.

Findings

Nonlinear effects significantly alter tidal dissipation rates.

Zonal flows' energy amplitude is affected by nonlinearities.

Angular momentum evolution impacts the dynamical evolution of systems.

Abstract

In close two-body astrophysical systems, such as binary stars or Hot Jupiter systems, tidal interactions often drive dynamical evolution on secular timescales. Many host stars and presumably giant gaseous planets feature a convective envelope. Tidal flows generated therein by the tidal potential of the companion can be dissipated through viscous friction, leading to the redistribution and exchange of angular momentum within the convective shell and with the companion, respectively. In the tightest systems, nonlinear effects are likely to have a significant impact on the tidal dissipation and trigger differential rotation in the form of zonal flows, as has been shown in previous studies. In this context, we investigate how the addition of nonlinearities affect the tidal flow properties, and energy and angular momentum balances, using 3D nonlinear simulations of an adiabatic and incompressible convective shell. In our study, we have chosen a body forcing where the equilibrium tide (the quasi-hydrostatic tidal flow component) acts via an effective forcing to excite tidal inertial waves in a spherical shell. Within this set-up, we show new results for the amplitude of the energy stored in zonal flows, angular momentum evolution, and its consequences on tidal dissipation in the envelopes of low-mass stars and giant gaseous planets.