Prof. Peng-Sheng Wei
National Sun Yat-Sen University, Chinese Taipei
Title: Solute Convection on Pore Shape Development in Solid
Abstract:
The effects of transport processes on the shapes of pores resulting from entrapped bubbles during solidification are numerically and theoretically investigated. Bubble formation results from supersaturation of dissolved gases in the liquid ahead of the solidification front. Pore formation and its shape in solid influence not only microstructure of materials, but also contemporary issues of biology, engineering, foods, geophysics and climate change, etc. In this study, equations of fluid flow, heat transfer and solute concentration are solved by using commercial COMSOL computer code. Scaling analysis shows that solute convection plays an important role inpore shape development during solidification. Solute convection influences not only thickness of solute concentration on the bubble cap, but also time for bubble entrapment. This work is critical to understand and control different types and sizes of pore shapes and their distributions in the solid in advance.
Biography:
Dr. Peng-Sheng Wei received Ph.D. in Mechanical Engineering Department at University of California, Davis, in 1984. He has been a professor in the Department of Mechanical and Electro-Mechanical Engineering of National Sun Yat-Sen University, Kaohsiung, Taiwan, since 1989. Dr. Wei has contributed to advancing the understanding of and to the applications of electron and laser beam, plasma, and resistance welding through theoretical analyses coupled with verification experiments. Investigations also include studies of their thermal and fluid flow processes, and formations of the defects such as humping, rippling, spiking and porosity. Dr. Wei has published more than 85 SCI journal papers with the corresponding author, delivered keynote or invited speeches in international conferences more than 120 times. He is a Fellow of AWS (2007), and a Fellow of ASME (2000). He also received the Outstanding Research Achievement Awards from both the National Science Council (2004), and NSYSU (1991, 2001, 2004), the Outstanding Scholar Research Project Winner Award from National Science Council (2008), the Adams Memorial Membership Award from AWS (2008), the Warren F. Savage Memorial Award from AWS (2012), and the William Irrgang Memorial Award from AWS (2014). He has been the Xi-Wan Chair Professor of NSYSU since 2009, and Invited Distinguished Professor in the Beijing University of Technology, China, during 2015-2017.