Liquid-jet dynamics revealed by ultrafast X-ray phase contrast imaging

Fast liquid jets and sprays, which are complex multiphase flow phenomena, have been one of physics' veiled mysteries ever since the pioneering work by Rayleigh in the 19^th century (See, W. S. Rayleigh, "On the stability of jets", Proc. Lond. Math. Soc. 4, 10 (1878)). The main reason is simply that standard microscopy and visible light imaging techniques cannot peer into the dark and murky centers of dense-liquid jets. Recently, Dr. K. Fezzaa and his colleagues (Argonne National Lab, USA) have succeeded in revealing for the first time the morphology and velocity fields of high-speed and highly turbulent jets generated by a gasoline direct injection system. The research group employed ultrafast synchrotron-X-ray full-field phase-contrast imaging. The spatial and time resolutions in the experiments were 5-30 micron and 472 ns, respectively. For more information on the present experiments, see the paper, "Ultrafast X-ray study of dense-liquid-jet flow dynamics using structure-tracking velocimetry", Y. Wang et al., Nature Physics, advanced online publication, DOI: 10.1038/nphys840