演讲主题：Clean Spray Combustion under High Temperature and High Pressure Environments
演讲人：Tiegang Fang, PhD （NC State University）
Compression-ignition engines using high-pressure spray combustion are attractive power stations for transportation applications due to their superior thermal efficiency and less greenhouse gas exhaust. New combustion modes, e.g. low temperature combustion (LTC), provide a unique approach for soot and NOx emission reduction. The application of LTC, however, poses significant challenges in engines with increased CO and HC emissions as well as difficulties in its control under high-load operating conditions. In this talk, we will discuss experimental investigations of spray combustion under different combustion modes in an optical constant volume chamber. The combustion and soot processes were visualized and measured through the application of advanced non-intrusive diagnostic techniques for different kinds of fuels. The combustion process was visualized by employing a multi-band imaging technique. Analyses were carried out for both transient and quasi-steady state stages. Flame structure under different modes will be discussed. Results of soot concentration and temperature using two-color pyrometry will be presented and the effects of ambient temperature and oxygen concentration will be analyzed. Soot measurements for different fuels will also be discussed. A new combustion regime under high ambient temperature and highly diluted conditions will be introduced and the results of soot temperature and concentration will be compared with LTC and conventional combustion modes. Finally, the results of biomass to liquid fuels will also be briefly discussed.
About the speaker
Tiegang Fang is an associate professor in the Mechanical and Aerospace Engineering Department at NC State University. He obtained his B.E. degree from Tsinghua University. Before receiving his Ph.D. from UIUC, he obtained his M.S. degree from the Mechanical and Aerospace Engineering department at Rutgers University. His research interests include internal combustion engines, alternative fuels including biofuels, high pressure spray combustion, soot, liquid breakup and atomization, optical diagnostics on reacting flows, heat and mass transfer, and fluid mechanics. He has published more than 120 SCI indexed journal and more than 50 conference papers. He received the top cited paper award from the Communications in Nonlinear Science and Numerical Simulations journal in 2012, the 2013 Alcoa Foundation Engineering Research Achievement Award from the College of Engineering at NC State University, the Ralph R. Teetor Educational Award from SAE International in 2014, and the Research Excellence award from the MAE department at NCSU in 2015. He is a member of a few professional societies including The Combustion Institute, the Society of Automotive Engineers (SAE), the Institute for Liquid Atomization and Spray Systems (ILASS), the American Society of Engineering Education (ASEE), and the American Society of Mechanical Engineers (ASME).