力学系与湍流国家重点实验室学术报告 - 9月11日 上午10-12点 - 两场报告
发布时间: 2015-09-07 09:16:00
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题目： Non-Equilibrium Plasma-Assisted Combustion - Enable New Reaction Pathways for Advanced Energy Conversion and Propulsion |
报告人: Prof. Wenting Sun (孙文廷)
Georgia Institute of Technology
报告内容摘要：
About 85% of the energy in the world is produced by the combustion of fossil fuels. However, the growing concerns about emissions, and the development of advanced energy conversion and propulsion systems have pushed traditional combustion technology to challenging limits. To continue to develop these technologies, it is critical to develop new approaches to improve the performance of combustion. This presentation will discuss controlling combustion kinetics using non-equilibrium plasmas - plasma-assisted combustion. Plasma introduces new chemical pathways into the combustion process. This plasma chemistry occurs on very different time scales compared to conventional combustion chemistry and also introduces a large number of new species and reactions which have not been previously considered in combustion research. Firstly, the kinetic enhancement mechanisms of non-equilibrium plasmas on combustion are investigated through plasma-flame interactions in counterflow systems at reduced pressure conditions. It is found that the radical production from the plasma can dramatically modify the reaction pathways of combustion to create a new flame region at low temperatures. Secondly, the effect of O3, which is a major product of plasma discharge, on flame propagation is investigated for a variety of fuels at elevated pressure conditions. Different reaction pathways control the effect of O3 addition depending on different pressure conditions and different fuels. Detailed enhancement mechanisms will be discussed to resolve the controversy in previous studies.
报告人简介：
Dr. Wenting Sun is currently an assistant professor of Georgia Institute of Technology, School of Aerospace Engineering. He received his B.E/M.E degrees from Tsinghua University, Department of Engineering Physics in 2005 and 2007, respectively, and Ph.D degree from Princeton University, Department of Mechanical and Aerospace Engineering in 2013. His current research focuses on plasma-assisted combustion, laser diagnostics and spectroscopy, and combustion kinetics for advanced energy conversion and propulsion systems. He has been awarded the Bernard Lewis Fellowship from the Combustion Institute, and Distinguished Paper Award at the 33rd International Symposium on Combustion.
时间：2015年9月11日（周五）上午10:00－11:00
地点：工学院1#楼210
（从北大东门 沿成府路北侧向东200米、再向北200米到工学院）
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题目：非均衡态纳秒脉冲等离子体对低压层流预混火焰的影响研究 |
报告人 李挺 副教授
北京航空航天大学
报告内容摘要：
等离子体强化燃烧作为燃烧学研究中的新兴领域在近10年来受到广泛关注。本研究采用能产生高折合电场强度(E/N)的纳秒脉冲等离子体，耦合进低压层流预混火焰，分别采用发射光谱，OH激光诱导荧光，氧原子激光诱导荧光等多种实验方法和化学反应动力模拟，探索等离子体对火焰影响的内在机理。研究发现由于非均衡态等离子体的作用，火焰悬浮位置明显向上游移动，表明火焰传播速度明显提升。通过激光诱导荧光测出火焰温度，OH浓度和氧原子浓度的空间和时间分布，结果显示由于耦合非均衡态纳秒脉冲等离子体，以上三个参数均大幅度提高。通过化学反应动力模拟，揭示了由于耦合等离子体，在火焰预混区域产生了大量氢原子，氧原子等自由基，极大地提高了该区域的化学反应速率，使燃烧链式反应在较低温的条件下开始反应，进而提升了该区域温度，与化学反应形成了正反馈，提升了火焰传播速度，使火焰向上游方向移动。
报告人简介：
李挺，北京航空航天大学副教授，硕士生导师。2014年12月博士毕业于美国俄亥俄州立大学； 2015年6月被聘为北京航空航天大学卓越百人副教授，任职于北航能源与动力工程学院。主要研究方向包括等离子体强化燃烧，等离子体流动控制，激光测量技术，等离子体反应动力学，合成脉冲射流，两相传热等。部分研究成果发表于Philosophical Transactions of the Royal Society A, Proceedings of the Combustion Institute, Combustion and Flame, Combustion Science and Technology, International Journal of Heat and Mass Transfer, ASME Journal of Heat Transfer等期刊.
时间：2015年9月11日（周五）上午11:00－12:00
地点：工学院1#楼210
（从北大东门 沿成府路北侧向东200米、再向北200米到工学院）
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