A model for meteoroid ablation including melting and vaporization

Abstract

Meteor influx and its physical properties can be estimated based on observations using heuristic models for ablation. These models suffer from a lack of validation and physical description of the flow and material fields, as well as their coupling. In this paper, we develop a model for meteoroid ablation including melting and vaporization, where both flow and material are coupled. We apply the model to ground experiments carried out at the arc jet facilities at NASA Ames Research Center. These experiments reveal a substantial effect of the shear ablation on the ablation process, which the heuristic models do not describe. Due to scarce data on physicochemical material properties at high temperatures, we perform a sensitivity analysis, showing that the material thermal conductivity and viscosity are essential parameters for the shear ablation process. We also observe that the direct evaporation phenomenon is negligible compared to the mass loss by shear ablation. Our models are used to compute an effective heat of ablation six times smaller than the one reported in the literature. These models can be applied to study meteor trajectories and to improve coefficients used in heuristic models.