The Possibility of the Kelvin-Helmholtz Instability during Sedimentation of Dust Grains in the Protoplanetary Disk

TL;DR

This paper investigates whether shear-driven turbulence, specifically Kelvin-Helmholtz instability, can occur during dust sedimentation in protoplanetary disks, considering dust growth, and finds it likely precedes gravitational instability.

Contribution

It demonstrates that dust growth influences the order of instabilities, showing Kelvin-Helmholtz instability occurs before gravitational instability, contrary to previous models without dust growth.

Findings

Kelvin-Helmholtz instability can occur before gravitational instability.

Dust growth affects the sequence of instabilities during sedimentation.

The results differ from previous studies that ignored dust growth.

Abstract

In this paper, we reexamine the possibility of shear-driven turbulence during sedimentation of dust grains in the protoplanetary disk. The shear-driven turbulence is expected to occur before the onset of the gravitational instability for MMSN model. While according to previous studies without taking account of growth of dust grains, with the larger abundance of dust grains, the gravitational instability is indicated to occur before shear-driven turbulence. In this paper, the case with dust growth is considered, and it is found that the Kelvin-Helmholtz instability tends to occur before the gravitational instability even in the case with large abundance of dust grains. This is different from previous results without the dust growth.