Tidal theory of the thermal wind

Scaling laws to understand tidal dissipation in fluid planetary regions and stars I - Rotation, stratification and thermal diffusivity

Tidal dissipation in planets and stars is one of the key physical mechanisms driving the evolution of star-planet and planet-moon systems. Several signatures of its action are observed in planetary systems thanks to their orbital architecture and the rotational state of their components. Tidal dissipation inside the fluid layers of celestial bodies are intrinsically linked to the dynamics and the physical properties of the latter. This complex dependence must be characterized. We compute the tidal kinetic energy dissipated by viscous friction and thermal diffusion in a rotating local fluid Car…

Low-Order Modelling of Blade-Induced Turbulence for RANS Actuator Disk Computations of Wind and Tidal Turbines

Modelling of turbine blade-induced turbulence (BIT) is discussed within the framework of three-dimensional Reynolds-averaged Navier-Stokes (RANS) actuator disk computations. We first propose a generic (baseline) BIT model, which is applied only to the actuator disk surface, does not include any model coefficients (other than those used in the original RANS turbulence model) and is expected to be valid in the limiting case where BIT is fully isotropic and in energy equilibrium. The baseline model is then combined with correction functions applied to the region behind the disk to account for the…

木卫二（Europa）的海洋将内部潮汐加热模式传递至冰-海边界

Europa's ocean translates interior tidal heating patterns to the ice-ocean boundary

本研究通过全球直接数值模拟发现，木卫二海洋对流可传递地幔潮汐加热的纬度变化至冰壳，地幔主导加热类型决定了冰壳厚度的极赤差异及经度变化特征。

Chaotic mean wind in turbulent thermal convection and long-term correlations in solar activity

It is shown that correlation function of the mean wind velocity in a turbulent thermal convection (Rayleigh number $Ra \sim 10^{11}$) exhibits exponential decay with a very long correlation time, while corresponding largest Lyapunov exponent is certainly positive. These results together with the reconstructed phase portrait indicate presence of a chaotic component in the examined mean wind. Telegraph approximation is also used to study relative contribution of the chaotic and stochastic components to the mean wind fluctuations and an equilibrium between these components has been studied. Since…

Numerical study of the McIntyre instability around Gaussian floating vortices in thermal wind balance

The visco-diffusive McIntyre instability (McIntyre 1970) has been suggested as a possible source for density layer formation around laboratory and oceanic vortices. This suggestion is here quantitatively addressed using idealised, axisymmetric, numerical simulations of a simple Gaussian-like vortex in thermal wind balance, floating in a rotating, stratified flow. Numerical simulations are complemented by a local stability analysis derived from the seminal study (McIntyre 1970). It is confirmed that the McIntyre instability is responsible for the layering observed around laboratory vortices, bu…