HEMI Seminar- Transport Phenomena in Compacted Granular Media: How mass, heat, and electron from in such materials

Granular media include everything from sand and rocks to flour and salt, and can display some characteristics of gases, liquids and solids. Granular media are commonly used in energy systems to store, convert, capture and produce energy. Examples include lithium-ion batteries, nuclear fusion reactors, and thermal storage systems. The function of granular materials in these energy systems involves essentially the transport of electrons, heat and mass. This talk will discuss the fundamental mechanics of granular materials arising from the inherent multi-scale, multi-phase and multi-physics nature. For electrical conduction, granular media were considered as random networks of resistors and capacitors, originated from interfacial electro-mechanical properties. These complex networks have been observed to exhibit intrinsic stress-dependent transport characteristics that show power law behavior with respect to the frequency of electrical signal. In terms of heat and mass transfer through the media, topological features are shown to play a significant role in determining the modes of transport. These results will be presented through a few specific examples. These advances on the mechanics of granular materials help to expand our fundamental understanding of the transport phenomena, for improving the functionality of energy systems and reduce their risks of failure.

Bio:

Dr. Yixiang Gan received the Dr.-Ing degree (with summa cum laude) in Mechanical Engineering from Karlsruhe Institute of Technology (KIT), Germany, in 2008. From 2009 to 2010, he continued worked at KIT as a research scientist on several European projects on nuclear fusion. In 2010, he joined The University of Sydney (USYD), first as a Postdoctoral fellow, then Lecturer and Senior Lecturer. His research areas include mechanics of granular and porous media, mechanics of interfaces, heat and electrical conduction, self-hearing in soils, and carbon geo-sequestration (More information via http://drgan.org/ and Twitter: @drgan).