报告内容：

The formation of a cloud of fine aluminum particles can pose a serious threat in a number of work environments. Most previous studies have focused on the combustion of single particles or on the combustion of dust clouds contained within rigid vessels. In the current study, the effect of scale on freely propagating flames in aluminum powder clouds is investigated in the lab. Using a stabilized Bunsen dust burner or by injecting a dust mixture into a balloon, and in the field in large-scale conical dust clouds several meters in height. Turbulence within the dust cloud in the larger scale experiments and radiation effects both contribute to increasing the flame speed in larger dust clouds compared with smaller scale clouds in the lab. During my talk 1 will show some videos of flame propagation in large-scale dust clouds.  I will also briefly describe some experiments in which we study metal dust flames in a microgravity environment and also some other experiments in which we study the formation of particle jets during explosive particle dispersal.

报告人简介：

David Frost is currently a Professor of Mechanical Engineering at McGill University in Montreal, Canada. He is also the Associate Chair of Curriculum Affairs of the Department of Mechanical Engineering. He received his PhD in Aeronautics at Caltech in 1985 in the area of explosive vaporization and spent a year as a postdoc there before moving to McGill. At McGill, his research interests have ranged from experimental work in explosive metal/water interactions to high-speed combustion processes in multiphase media and shock/material interactions. His current interests include metal combustion and explosive dispersal of particles and liquids with an emphasis on optical diagnostic techniques. He is on the editorial board member of Shock Waves, and has over 70 articles on international journals such as Proceedings of the Combustion Institute, Combustion and Flame, Physics of Fluids, Applied Physics Letters, Journal of Propulsion and Power, etc.