title: Simultaneous measurement of bubble size, velocity and void fraction in two-phase bubbly flows with time-resolved X-ray imaging.
abstract: Key parameters of two-phase flows, such as void fraction and microscale bubble size, shape and velocity, were simultaneously measured using time-resolved X-ray imaging. X-ray phase-contrast imaging was employed to obtain those parameters on microbubbles. The void fraction was estimated from X-ray absorption. The radii of the measured microbubbles were mostly smaller than 20 µm, and the maximum velocity was 39.442 mm s(-1), much higher than that in previous studies. The spatial variations of the void fraction were consecutively obtained with a small time interval. This technique would be useful in the experimental analysis of bubbly flows in which microbubbles move at high speed.
authors.affiliation: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyojadong, Pohang 790-784, Republic of Korea.
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Jung
authors.affiliation: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyojadong, Pohang 790-784, Republic of Korea.
authors.forename: Han Wook
authors.initials: HW
authors.lastname: Park
authors.affiliation: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyojadong, Pohang 790-784, Republic of Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D000465:Algorithms; D003952:Diagnostic Imaging / Q000379:methods; D006358:Hot Temperature; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D045423:Microbubbles; D012212:Rheology; D017356:Synchrotrons; D013995:Time; D014867:Water; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D014867:Water
keywords: X-ray imaging; bubble size; bubble velocity; bubbly flow; void fraction