Streaming instability in the quasi-global protoplanetary discs

TL;DR

This paper studies streaming instability in protoplanetary discs using numerical simulations and linear stability analysis, revealing rapid dust clumping driven by gas-dust velocity differences, with results consistent across different computational methods.

Contribution

It introduces a multi-fluid extension of the Relaxing TVD scheme in PIERNIK for simulating streaming instability, validating its effectiveness against other methods.

Findings

Rapid dust clumping due to azimuthal velocity differences

Amplification of initial density perturbations by several orders of magnitude

Numerical results compatible with linear stability analysis and other methods

Abstract

We investigate streaming instability using two-fluid approximation (neutral gas and dust) in a quasi-global, unstratified protoplanetary disc, with the help of PIERNIK code. We compare amplification rate of the eigen-mode in numerical simulations, with the corresponding growth resulting from the linear stability analysis of full system of Euler's equation including aerodynamic drag. Following Youdin & Goodman (2005) we show that (1) rapid dust clumping occurs due to the difference in azimuthal velocities of gas and dust, coupled by the drag force, (2) initial density perturbations are amplified by several orders of magnitude. We demonstrate that the multi-fluid extension of the simple and efficient Relaxing TVD scheme, implemented in PIERNIK, leads to results, which are compatible with those obtained with other methods.