Measuring the Influence of Ablation on Hypersonic Plasma Trails in ISL's Hyperballistic Tunnel by means of Radar: Simulation and Experiment

Abstract

Plasma generation in hypersonic flight affects electromagnetic sensing and detection [1, 2]. These effects are also influenced by ablation arising at higher Mach numbers and in denser atmospheres [3, 4]. This study investi- gates the ablation’s impact on hypersonic radar signatures utilizing a hyperballistic tunnel, a wideband radar system with high PRF, and complimentary measurement techniques including X-Ray radiography and high speed cameras to monitor the ablation process. Spherical aluminum and C/C-SiC projectiles are fired at velocities between 2.5 km s−1 and 4.6 km s−1 into different atmospheres. At extreme conditions, aluminum serves as ablator, while the less reactant C/C-SiC acts as a non-ablative reference. Acquired radar signatures are compared with CFD and CEM simulations. This study showcases the ability of surface material to alter the radar signatures due to plasma formation and ablation during hypersonic flights.