Breakup of Single Droplet Induced by High Weber Number Flow behind Shock Wave

The formation of fragments resulting from the breakup of a single droplet owing to a high-velocity gas flow behind a shock wave was captured through high-resolution imaging with temporal and spatial accuracy. The process of fragment formation was also examined. The catastrophic breakup of a droplet in the high Weber number region is characterized by an upstream interfacial wave with a wavelength larger than the critical wavelength of the Kelvin-Helmholtz instability in the stability region. The observed wavelength is consistent with the theoretical wavelength of the Rayleigh-Taylor instability. Therefore, the upstream interfacial wave of the droplet is generated by the development of small disturbances owing to the Rayleigh-Taylor instability. The measured fragment diffusion widths were found to be independent of Weber number.