Space debris interaction across a two-dimensional oblique shock wave

The accumulation of space debris objects on Earth's orbit is raising environmental and safety concerns yielding an urgent need to develop Design for Demise methodologies. Free-flight testing in hypersonic wind tunnels has shown superior capabilities to conventional sting-supported model experiments using aerodynamic balances for analyzing debris objects, providing accurate aerodynamic databases, and testing fragment separation scenarios. An upgraded image processing methodology has been applied to investigate experimentally the aerodynamics of a free-flying inter-stage rocket element that interferes with a two-dimensional oblique shock wave. The study was carried out in the VKI Longshot facility in Mach 14 cold hypersonic flow. The annular ring model was initially suspended at 90 degrees, 60 degrees, 0 degrees incidence upstream of a transversely mounted cylinder. Upon the arrival of the flow, the model is automatically released, flies freely and interferes with a two-dimensional shock generated by a steady crossflow cylinder. The interference induces a notable flow-normal velocity even at early stages of the interaction, promoting a shock wave surfing motion. The comparison of the experiments showed that when such an irregular object interferes with an oblique shock wave, the result of the interaction highly depends on the way the shock wave is crossed.