HYPERVELOCITY IMPACT FRAGMENT CLOUDS IN HIGH PRESSURE GAS NUMERICAL AND EXPERIMENTAL INVESTIGATIONS

摘要

Space debris poses a threat to vehicles in near earth orbits. Due to the potential risk of catastrophic bursting under hypervelocity particle impact, pressurized vessels have been identified as high risk components. During recent experimental studies the principle failure mechanisms were investigated that lead to qualitative descriptions of the phenomenology. First experimental results from different studies showed that a strong interaction between cloud fragments and pressure gas occurred. In some cases the fragments were completely ablated inside the vessel. The aim of this study was the numerical simulation of the complex interaction between fragments and gas. The numerical work was performed in parallel to experiments, where hypersonic fragment clouds in pressure gas were photographed. The pictures obtained in the experiments shoed black regions behind the leading edge of the cloud which are assumed to be filled with ablation products. A distinct blast wave formation behind the fragments was observed in the surrounding gas, Also, particularly at high pressures, a size dependent deceleration of the fragments leads to the formation of a jet-like spike along the impact axis.