Motion of a fragmented meteoroid through the planetary atmosphere

Meteor observations and crater field investigations support the view that s ome meteoroids undergo fragmentation into a finite number of splinters whic h move a long distance without further disruption. The motion of these frag ments cannot be described in the frame of liquid-like models. The primary p urpose of this study is to achieve some success in improving the alternativ e model of separate fragments, which is based on studying the motion of a f inite number of fragments interacting with each other through the air press ure. The three-dimensional (3-D) numerical technique is elaborated for the direct modeling of the flow around several arbitrarily arranged fragments. The model allows us to calculate the ablation mass rate and aerodynamic loa ding for each fragment. The new approach (hybrid model) based on the simult aneous solution of the 3-D hydrodynamic equations for the airflow and the d ifferential equations for the motion of discrete particles is proposed to s tudy the debris cloud evolution, taking into account successive fragmentati on. The simplified version of this model was applied to the Sikhote-Alin me teorite shower, Benesov bolide, and small meteoroids' impacts against the M artian surface.