Analysis of Processes Accompanying Cylindrical Cumulation

Flow contraction within cylindrical samples causes instability in motion, leading to the formation of circumferential compression stress. This then results in perturbations in the form of Mach three-shock configurations (protrusions) at the shock front. The area at the front of the perturbed shock wave increases due to these protrusions. Furthermore, the protrusions are amplified as a consequence of the absorption of smaller perturbations, which are continuously generated at the shock front. The shock front undergoes sharp growth at the final stage, giving rise to several large protrusions that divide it into separate sectors. These sectors undergo oscillatory movements. As the counter configurations collide, a high-pressure zone is generated, which propels some of the compressed material forward. The protrusions reach their maximum height when they become equal to the distance of the front to the axis. The near-axis region is taken up by the frontal protrusions, and the consequent rarefaction shock wave decelerates the incoming flow.