A computer model and parametric study of Earth-atmospheric entry of meteors

This investigation involves the physics of meteors entering the Earth's atmosphere. A computer model coded in FORTRAN is developed that simulates the trajectory of such bodies through the atmosphere. Both new and old techniques are used to simulate the various aspects of the problem physics. An improvement is made over previous work primarily in the radiative heat transfer and ablation models. To this end a new, estimation technique for the thermodynamic properties of high-pressure, high-temperature equilibrium air is devised. This new radiative model produces energy fluxes and ablation rates much lower than previously calculated, and this significantly affects the predicted trajectory of the meteors. For a given bolide, the model predicts deeper penetration and lower airburst heights than calculated by previous models. As proven by the Tunguska event of 1908, catastrophic disruptions in the lower atmosphere can have devastating effects, and it is almost certain that the airburst altitude is of consequence. The code is used to conduct a parametric study involving a wide range of meteors of different materials, body sizes, entry speeds and entry angles; the main result of interest is the airburst height achieved by the various cases. The study shows that stronger, denser bodies penetrate deeper into the atmosphere and deliver the most destructive power. The lighter bodies tend to ablate away more and are slowed down more easily by the atmosphere.