Protoplanetary Disk Turbulence Driven by the Streaming Instability: Nonlinear Saturation and Particle Concentration

摘要: We present simulations of the nonlinear evolution streaming instabilities in protoplanetary disks. The two components disk, gas treated with grid hydrodynamics and solids as superparticles, are mutually coupled by drag forces. find that initially laminar equilibrium flow spontaneously develops into turbulence our unstratified local model. Marginally (that couple to on a Keplerian timescale) trigger an upward cascade large particle clumps peak overdensities above 100. evolve dynamically losing material downstream radial drift while receiving recycled from upstream. Smaller, more tightly produce weaker transient smaller length scales. net inward is decreased for marginally particles, whereas particles migrate faster saturated turbulent state. diffusion solid measured their random walk, depends strongly stopping time solids-to-gas ratio background state, but generally modest, particularly solids. Angular momentum transport too weak wrong sign influence stellar accretion. Self-gravity collisions will be needed determine relevance planetesimal formation.