A smoothed particle hydrodynamics algorithm for multigrain dust with separate sets of particles

TL;DR

This paper introduces a smoothed particle hydrodynamics method for simulating gas and multiple dust grain species with different sizes, capturing their differential backreaction and improving accuracy over previous single-species models.

Contribution

The method allows for multi-species dust simulation with differential backreaction, advancing the modeling of dust-gas interactions in protoplanetary discs.

Findings

Accurately reproduces linear wave and shock solutions

Robustly models radial drift in discs

Effective for high dust-to-gas ratios

Abstract

We present a method for simulating the dynamics of a mixture of gas and multiple species of large Stokes number dust grains, typical of evolved protoplanetary discs and debris discs. The method improves upon earlier methods, in which only a single grain size could be represented, by capturing the differential backreaction of multiple dust species on the gas. This effect is greater for large dust-to-gas ratios that may be expected in the later stages of the protoplanetary disc life. We benchmark the method against analytic solutions for linear waves, drag and shocks in dust-gas mixtures, and radial drift in a protoplanetary disc showing that the method is robust and accurate.