Three dimensional atmospheric entry simulation of a high altitude cometary dustball meteoroid

Abstract

Aims. The break-up of a dustball meteoroid is investigated numerically based on fluid dynamics simulations of the meteoroid's atmospheric entry flow. Both thermal and mechanical break-up mechanisms are implemented, in order to investigate dustball meteoroid disintegration. Methods. A three dimensional model of a dustball meteoroid composed of thousands of small spherical grains was used in the atmospheric entry flow simulation, performed with the direct simulation Monte Carlo (DSMC) method. The dynamics of each meteoroid grain were calculated by means of the discrete element method (DEM), which models contact dynamics between grains. By coupling DEM with DSMC, the dynamics of a dustball meteoroid were calculated during atmospheric entry. In addition, thermal computations were also carried out taking into account the incoming atmospheric heat flux, thermal radiation, and grain ablation. Thus, this methodology is able to compute mechanical as well as thermal dustball meteoroid disintegration. Results. To test this novel multi-physics simulation framework, a prototypical dustball meteoroid, namely a Draconid meteoroid, was simulated. Using typical material properties from the literature, the Draconid meteoroid was compressed due to aerodynamic forces to roughly half its size immediately after the start of the simulation at 200 km altitude. Later, aerodynamic-induced meteoroid rotation occured until the meteoroid disintegrated mechanically at 120 km altitude. The fact that the meteoroid disintegrated mechanically is directly related to the combination of material properties used in the simulation. © 2021 ESO.