Multiphase Hydrodynamic Instability with Application to Planetary Nebulae Evolution
Abstract
Hydrodynamic Instability has many natural and engineering applications that have attracted scientists from hundreds of years ago to present. A special kind of hydrodynamic instability, the Shock-Driven Multiphase Instability (SDMI), is involved in the processing of cosmic dust and in the evolution of dust-gas flows in planet formation, super novae evolution, and planetary nebulae evolution. This research presents a preliminary numerical exploration of multiphase flows in the evolution of an Asymptotic Giant Branch (AGB) star toward planetary nebulae. Simulations are performed using the FLASH CODE developed in FLASH Center at University of Chicago. An experimental validation is first presented using data from shock tube experiment to compare the morphology of SDMI from high-speed planar laser imaging methods. In simulation, the particle-in-cell method was used with the two-dimensional Euler equations and solved using directionally split piecewise-parabolic method (PPM). This method was then adapted for the astrophysics regime by implementing a new drag model for high vacuum flows. Additionally, gravitational forces and radiation forces were added to the particles to simulate the dust outflow from an AGB star. Preliminary simulations of the dust-gas evolution around an AGB star, transitioning towards a planetary nebula are then presented. These simulations show that perturbations in the dust and radiation fields act to seed hydrodynamic instabilities in the dust-gas flow fields.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2019
- Bibcode:
- 2019APS..DFDM02053A