Aerodynamic Interaction of Multiple Bodies in Hypersonic Flow

Abstract

Asteroids and space debris pose a significant threat, which is becoming more relevant for the protection of the population and for the safe and sustainable use of space. Aerodynamic phenomena that occur during the atmospheric entry of these objects from outer space are crucial for the reliable prediction of the flight trajectories and the impact footprint of surviving fragments. This work takes a new look at how the aerodynamic behavior of single and multiple blunt bodies traveling at hypersonic speed affect their motion. The influence of the body shape and orientation on its aerodynamics and stability is the focus of this publication. Free-flight experiments have been carried out in the hypersonic wind tunnel H2K at the German Aerospace Center (DLR) in Cologne with single and tandem body arrangements of spheres, cubes and cylinders. High-speed stereo-tracking captured the model motions during free-flight, and high-speed schlieren videography provided documentation of the flow topology. Motion derivatives and aerodynamic coefficients have been determined in an extensive post-processing. The observed phenomena for multiple objects include different types of shock-shock interactions and wake-shock interactions. In this research, the results show that the geometry of the body has an immense influence on the aerodynamic loads and thus on the motion behavior.