Effect of the heat transfer coefficient on modelling the energy deposition of destructed meteoroid

Models of meteoroid destruction into the cloud of fragments moving with a common shock wave are considered: the two-parameter model that takes into account changes of the shape and density of the cloud, and simple models that leave these factors out of account, including those used in the literature. Models differ in equations governing the lateral expansion of the cloud. We numerically simulate the interaction of the Chelyabinsk asteroid with the Earth’s atmosphere by solving the meteor physics equations using fragment cloud models, and study the models abilities to reproduce the observational energy deposition curve. Heat transfer coefficient effect on simulating energy deposition using different models is estimated. For simple fragment cloud models, the optimal coefficient in the cloud lateral expansion equation is proposed as a function of the heat transfer coefficient (ablation parameter) to match the observational altitude of the bolide peak brightness. The optimal value of the uncertainty parameter in the expression for the heat transfer coefficient is found to match also a shape of the observational energy deposition curve. It is shown that the optimal simple and the two-parameter models give results of modelling the energy deposition of the Chelyabinsk asteroid and estimates of its entry mass, which are very close to each other and are consistent with the observational data.