Two-dimensional Numerical Study for Rayleigh-Taylor and Richtmyer-Meshkov Instabilities in Relativistic Jets

TL;DR

This study uses 2D relativistic hydrodynamic simulations to analyze how Rayleigh-Taylor and Richtmyer-Meshkov instabilities can disrupt non-rotating jets, highlighting the importance of the inertia ratio for stability.

Contribution

It reveals that these instabilities can spontaneously destroy cylindrical jets through radial oscillations driven by energy conversion, with a specific inertia ratio threshold for stability.

Findings

Instabilities can destroy cylindrical jet structures.

Radial oscillations are driven by energy conversion.

Inertia ratio determines jet stability threshold.

Abstract

We study the stability of a non-rotating single-component jet using two-dimensional special relativistic hydrodynamic simulations. By assuming translational invariance along the jet axis, we exclude the destabilization effect by Kelvin-Helmholtz mode. The nonlinear evolution of the transverse structure of the jet with a normal jet velocity is highlighted. An intriguing finding in our study is that Rayleigh-Taylor and Richtmeier-Meshkov type instabilities can destroy cylindrical jet configuration as a result of spontaneously induced radial oscillating motion. This is powered by in-situ energy conversion between the thermal and bulk kinetic energies. The effective inertia ratio of the jet to the surrounding medium $\eta$ determines a threshold for the onset of instabilities. The condition $\eta < 1$ should be satisfied for the transverse structure of the jet being persisted.