The discrete element method (DEM) is a powerful simulation tool which provides the details of the flow of individual particles and facilitates quick parametric studies, eliminating the need for expensive experimental testing. This presentation will outline advances in DEM to simulate the motion of cohesive and/or aspherical particles. Aspherical grains are described either as perfect cylinders or disks of varying aspect ratio or described using a linked and overlapping sphere approach. Using this linked approach, the flow of flexible aspherical particles can also be treated via a bonded particle model which incorporates normal and shear forces as well as bending and torsional moments. The bonded particle model also allows for breakage of aspherical particles during impact. Cohesion between particles is described as originating either from surface moisture, described by a liquid bridge force model in the case of pendular liquid bridges, or from van der Waals interactions, described by the adhesive JKR model. DEM simulations are validated via experiments of hopper flow/discharge and measurements of particle-phase stress in a ring shear cell.
Jennifer Sinclair Curtis is Distinguished Professor of Chemical Engineering and Dean of Engineering at University of California, Davis. Her research focuses on the development and validation of particle flow models which have been extensively adopted by both commercial and open source CFD software packages. She was the first to partner with ANSYS Fluent to greatly expand the multi-phase simulation capability of the code which is used by 96 of the 100 biggest industrial companies in the world and over 40,000 customers. Her particulate flow models are also included in the CFD Research Corporation software package and the open-source CFD codes OpenFOAM and MFIX. She is a Fellow of APS, AAAS, ASEE and AIChE. She is recipient of AIChE’s Particle Technology Forum’s Lifetime Achievement Award, a Fulbright Senior Research Scholar Award, AIChE's Thomas-Baron Award in Fluid- Particle Systems, ASEE’s Chemical Engineering Lectureship Award, ASEE’s Benjamin Garver Lamme Award, ASEE’s CACHE Award for Excellence in Computing in Chemical Engineering Education, ASEE's Sharon Keillor Award for Women in Engineering, and the NSF Presidential Young Investigator Award. She also received the Van Antwerpen Award – the highest award for service to the Institute by the AIChE Board of Directors. She received her PhD in Chemical Engineering from Princeton University and her BS in Chemical Engineering from Purdue University which recently recognized her as a distinguished engineering alumna. She currently serves as Co- Chair of the National Academies’ Board on Chemical Sciences and Technology.