Unsteady numerical analysis of drag on non-winged hypersonic vehicle during re-entry

Document Type : Original Article


Aerospace Engineering Department, Military Technical College, Cairo, Egypt.



Reentry vehicles, such as upper stages of ballistic missiles, experience severe aerodynamic loads during the reentry phase of trajectory. This phase is characterized by three aspects namely, the continuous change in atmospheric conditions, the hypersonic flight speed, and the unsteady flight of the vehicle itself. Understanding the aerodynamic features of the vehicle during reentry phase is crucial to the designers of such vehicles. The objective of the present study is to investigate the aerodynamic features of a generic bi-cone non-winged vehicle that accelerates during reentry through the upper layer of dense atmosphere. The investigation is conducted via numerically simulating the unsteady flow around the vehicle using a commercial transient laminar CFD solver. The unsteady simulation accounts for the temporal variation of freestream conditions and the linear acceleration of the vehicle during descent. The used CFD model is validated against available wind tunnel data of a similar vehicle. The results address the evolution of the flow field pattern as well as the temporal variation of drag acting on the vehicle during reentry.