讲座题目：Advanced Optical Imaging for Multiphase Flow Research
讲座内容：Optical imaging provides a power tool for visualizing and quantifying flow and particle dynamics in various applications related to fluid mechanics. When applied to multiphase flow problems, however, it faces major challenges associated with the mismatch of optical properties between the dispersed and continuous phases. In this talk, we will present some novel optical imaging techniques extended from conventional particle image velocimetry (PIV) and some examples for probing flow across liquid-gas interface and the dynamics of dispersed phases in multiphase flows. Specifically, we will talk about two technical innovations, i.e., the dynamic interface correction and advanced holographic imaging. The former technique is used to minimize the distortion generated from optical imaging through liquid-gas interface, allowing us to probe into the internal gas flow structures inside a ventilated cavity. The latter is a computational imaging technique that combines holographic reconstruction, inverse regularized optimization and the latest deep learning methods, enabling high-fidelity characterization of 3D position, shape and orientation of dispersed phases in the flow. The applications of this technique to the measurements of bubbly flows and sprays, etc. will be discussed in this talk.
Jiarong Hong is a tenured associate professor in Mechanical Engineering Department and Saint Anthony Falls Laboratory at University of Minnesota. He received his bachelor degree from University of Science and Technology of China in 2005, M.S. and Ph.D. from Johns Hopkins University in 2008 and 2011, and started his career in University of Minnesota in 2012. His research is focused on understanding the dynamic processes involved in the interaction between flow and environment, with innovative approach and instrumentation to tackle the challenges in the measurements of complex flow fields, for a wide range of applications. Hong is a recipient of National Science Foundation CAREER award, Office of Naval Research Young Investigator award and McKnight Land-grant Professorship from University of Minnesota.