Measurement of traveling pressure waves inside a droplet
Abstract
Shock wave-droplet interactions have been receiving increasing attention due to their relevance in aviation fuel combustion and minimally invasive medical treatments, yet quantifying them experimentally remains a challenge. In this study, we propose a background-oriented schlieren (BOS) technique for quantitative spatiotemporal measurements of shock wave-droplet interaction, employing a novel ray-tracing correction, a synchronization system, and a projected background. Underwater shock waves propagating both inside and outside a millimetric perfluorohexane droplet immersed in water are experimentally measured. The quantified density-gradient and pressure fields are compared with numerical simulations, and the BOS measurements-including sound speeds, the shock-focusing location, and the maximum pressure-are found to be in close agreement with the numerical results. Notably, the technique successfully captures the phase shift before and after shock focusing that had previously only been hypothesized.
Cite
@article{arxiv.2603.21905,
title = {Measurement of traveling pressure waves inside a droplet},
author = {Sayaka Ichihara and Samuele Fiorini and Yoshiyuki Tagawa and Outi Supponen},
journal= {arXiv preprint arXiv:2603.21905},
year = {2026}
}