Dr. Xinyu Zhang, Assistant Professor

Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Science and Engineering, University of Nottingham Ningbo China, China

Biography:  Dr. Xinyu Zhang received his BEng. (1985), MEng. (1994), and Dr. Eng. (1998) Degrees from Energy Engineering at Zhejiang University. He received his PhD in Mechanical Engineering at Clarkson University in 2009. He was a University Post-Doctoral Fellow in Chemical Engineering at the Ohio State University in 2000. Currently, he is an Assistant Professor of Mechanical Engineering at the University of Nottingham Ningbo China since 2012. He is an Associate Fellow of HEA (Higher Education Academy), member of ASME (American Society of Mechanical Engineers) and AAAR (American Association for Aerosol Research), and Senior Member of AICHE (American Institute of Chemical Engineers). His main research interests cover multiphase flows, aerosol dynamics, energy systems, and renewable/clean energy. He has over 140 publications, talks and posters with 520 citations. He performed over 70 paper review activities for dozens of journals and conferences. He has 28 years interdisciplinary research experience in Energy Engineering, Chemical Engineering, Mechanical Engineering and Environmental Engineering.

Topic: Numerical Simulations of Liquid–Gas–Solid Flows in Three–phase Slurry Reactors

Abstract: A fully coupled Eulerian-Lagrangian computational model for simulations of gas-liquid-solid flows in three–phase slurry reactors is developed. In this approach, the liquid flow is modeled using a volume-averaged system of governing equations, whereas motions of bubbles and particles are evaluated by Lagrangian trajectory analysis procedure. Bubble shape variations are neglected and the two-way interactions between bubble-liquid and particle-liquid are included in the analysis by deleting the volume taken by bubbles and particles from liquid. The discrete phase equations include drag, lift, buoyancy, and virtual mass forces. Particle-particle interactions and bubble-bubble interactions are accounted for by the hard sphere model approach. The particle-bubble interactions and bubble coalescence are also included in the model. The transient flow characteristics of the three-phase flow are studied and mechanisms and characteristics of gas - liquid - solid three-phase flows are discussed. The results are compared with the available experimental data. The effects of bubble size and gravity are analyzed. The results show that bubble size and gravity has magnificent effects on the flow characteristics of three-phase gas-liquid-particle flows in bubble columns. The three-phase velocities of the flows with larger bubbles or under higher gravity are larger than those of the flows under normal gravity are. The flows with larger bubbles or under higher gravity develop fast. Bubbles and bubble volume fraction in the higher gravity flows are smaller.