Debris Aerodynamic Interaction and its Effect on Reentry Risk Assessment

Aerodynamic interactions of objects in a continuum hypersonic and supersonic flow are numerically and analytically investigated for perfect and thermochemical equilibrium gas conditions. An innovative semi-analytical methodology has been developed and associated to the Laurence equations [4] in order to compute the aerodynamics coefficients of a sphere located downstream the shock wave issued from a primary object. The influence of the aerodynamic interactions on the trajectory of a debris cloud during atmospheric re-entry has also been assessed and compared to the trajectory of the same noninteracting objects. Finally, the influence of fragments interactions on heat flux and debris survivability during the re-entry has been investigated.