受能动学院吴东垠教授邀请，美国北卡州立大学方铁钢教授，于2016年6月30日到7月8日访问我校，并就可再生替代燃料的清洁燃烧和喷雾过程中破碎的机理做两场学术报告，欢迎大家积极参加。该项目得到“西安交通大学短期外国文教专家聘请计划”的资助。
讲座人介绍：
方铁钢博士现在是北卡罗莱纳州州立大学(NC State University)机械与航空工程系的副教授，研究方向包括内燃机，可替代燃料及生物燃料，高压喷雾燃烧，液滴破碎及雾化，化学反应流体的光学测量等等。已发表SCI期刊论文110余篇，会议论文30余篇，2012年荣获COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICALSIMULATION颁发的高引用文章奖，2013年荣获北卡州立大学工学院颁发的AlcoaFoundationEngineering Research Achievement Award，2014年荣获国际自动机工程师学会颁发的Ralph R. Teetor Educational Award， 以及2014年中国物理学会颁发的最有影响论文奖一等奖。方铁钢博士是国际自动机工程师学会、国际液体雾化与喷雾系统学会、美国工程教育学会和美国机械工程师学会的会员，现致力于研究可再生替代燃料的清洁燃烧和喷雾过程中的破碎机理。
讲座一时间：2016年7月6日上午10点
讲座一地点：东三甲205教室
讲座一内容：Clean Spray Combustion under High Temperature and High Pressure Environments
内容简介：
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 including ultra low sulfur No.2 diesel, biodiesel, as well as a new biofuel derived from biomass. 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 dilutedconditions will be introduced and the results of soot temperature and concentration will be compared with LTC and conventional combustion modes. Finally, the applications of fuel in water emulsions in diesel engines will also be briefly discussed.
讲座二时间：2016年7月7日下午4点
讲座二地点：东三甲205教室
讲座二内容：Investigation on the Mechanism of Liquid Breakup and Atomization
内容简介：
Liquid breakup and atomization have important applications in industries processes such as fuel combustion, painting, irrigation, coating, and so forth. Understanding the mechanism of involved physical process is essential for controlling the breakup and atomization process. In this talk, effects of nozzle geometry will be first discussed for low-pressure liquid jets. The breakup regime was classified based the Ohnesorge chart for non-circular orifices including rectangular, square, and triangular shapes. Axis-switching phenomenon was analyzed for rectangular jet. It is demonstrated that orifices with sharp corners can generate more jet instability and lead to shorter breakup length. Then fuel sprays related to diesel engine combustion under high pressures will be covered. The effects of fuel property, orifice geometry, and fuel injection pressure were investigated. Fuel atomization of renewable diesel fuel was measured and compared with No.2 diesel, biodiesel, and jet fuels. It is demonstrated that increasing fuel injection pressure can help reduce drop size. Compared with circular orifice, non-circular orifices show axis-switching phenomenon and produce larger spray plume and larger spray angle. It is also observed that the fuel atomization for non-circular orifices generate very complicated behavior, significantly depending on the location, fuel injection pressure, and measuring orientation. Finally, a new fuel injection system with the capability of providing up to 870 MPa fuel pressure will be discussed. Due to the limitation of available fuel injection devices, a relatively low pressure of up to 250 MPa was used in the experiments. Spray penetration length and penetration velocity were analyzed for different injection pressures. Shock waves were visualized by a Schlieren technique and a 250 MPa pressure produces strong shock waves. Results also show that in order to achieve extremely high pressure fuel injection, new injection devices or modifications on existing fuel injectors are needed for further studies.
