Atmospheric entry and strewn fields estimation for rubble-pile meteoroids

One of the potentially catastrophic risks to human survival is the impact of a meteorite on Earth. When a meteoroid enters the atmosphere at an ultra-high speed, a series of complex evolution processes occur, mainly including ablation, fragmentation, airburst, and ground impact. This paper proposes a new systematic dynamical method for simulating the entire process of a meteoroid entering the atmosphere. In the new method, the DEM (Discrete Element Method) model is utilized to describe the initial structure and shape of a rubble-pile meteoroid. A combination of an aerodynamic trajectory model, a thermal ablation model, and an airburst model is introduced to simulate the entry process. Particularly, the Jone-Wilkins-Lee state equation is employed to characterize the large-scale airburst phenomenon caused by the internal expansion of the meteoroid. Referring to the observational data of the Chelyabinsk meteorite event, this paper parametrically simulates the trajectories, ablation, fragmentation, and airburst, and predicts the strewn field of different-shaped meteoroids. Compared with existing debris cloud models, this method considers the shape effect of rubble-pile meteoroids and can obtain the strewn field as a side effect. Numerical validation is carried out, indicating the result of the new method is more in line with the actual scenarios.