Clusters of heavy particles in two-dimensional Keplerian turbulence

Abstract

Protoplanetary disks are gaseous systems in Keplerian rotation around young stars, known to be turbulent. They include a small fraction of dust from which planets form. In the incremental scenario for planet growth, the formation of kilometer-size objects (planetesimals) from pebbles is a major open question. Clustering of particles is necessary for solids to undergo a local gravitational collapse. To address this question, the dynamic of inertial particles in turbulent flows with Keplerian rotation and shear is studied. Two-dimensional direct numerical simulations are performed to explore systematically two physical parameters: the rotation rate, which depends on the distance to the star, and the particle response time, which relates to their size. Shear is found to drastically affect the characteristics of the turbulent flow destroying cyclones and favoring the survival of anticyclones. Faster Keplerian rotation enhances clustering of particles. For intermediate sizes, particles concentrate in anticyclones. These clusters form in a hierarchical manner and merge together with time. For other parameter values, solids concentrate on fractal sets that get more singular with rotation. The mass distribution of particles is then found to be multifractal with small dimensions at large orders, intriguing for triggering their gravitational collapse. Such results are promising for a precise description and better understanding of planetesimal formation.

arXiv comment16 pages, 21 figures

References in corpus (23)

• Dynamics of Protoplanetary Disks
• Protoplanetary Disk Turbulence Driven by the Streaming Instability: Non-Linear Saturation and Particle Concentration
• Fractal clustering of inertial particles in random flows
• Particle Aggregation in a turbulent Keplerian flow
• On the relevance of subcritical hydrodynamic turbulence to accretion disk transport
• Resonant Drag Instabilities in protoplanetary disks: the streaming instability and new, faster-growing instabilities
• A highly settled disk around Oph 163131
• Hydrodynamic stability of rotationally supported flows: Linear and nonlinear 2D shearing box results
• Coherent structures and extreme events in rotating multiphase turbulent flows
• Large scale inhomogeneity of inertial particles in turbulent flow
• Streaming Instability in Turbulent Protoplanetary Disks
• How efficient is the streaming instability in viscous protoplanetary disks?
• Turbulence Regulates the Rate of Planetesimal Formation via Gravitational Collapse
• Intermittency in two-dimensional Ekman-Navier-Stokes turbulence
• Hydro-, Magnetohydro-, and Dust-Gas Dynamics of Protoplanetary Disks
• Persistence Problem in Two-Dimensional Fluid Turbulence
• Ergodic and non-ergodic clustering of inertial particles
• Cascade Model for Planetesimal Formation by Turbulent Clustering
• Angular momentum transport and large eddy simulations in magnetorotational turbulence: the small Pm limit
• The Streaming Instability Cannot Form Planetesimals from mm-size Grains in Pressure Bumps
• Vortices in stratified protoplanetary disks : From baroclinic instability to vortex layers
• Dust Coagulation Regulated by Turbulent Clustering in Protoplanetary Disks
• Spotted Disks

Cited by in corpus (3)

• Trapping and extreme clustering of finitely-dense inertial particles near a rotating vortex pair
• Reduction of dust radial drift by turbulence in protoplanetary disks
• Planetesimal gravitational collapse in a gaseous environment: Thermal and dynamic evolution