Using DEM to develop constitutive models for CFD simulations of aspherical particulate flow mixtures

The discrete element method (DEM) is a powerful, yet computationally-intensive, simulation tool which provides the details of the flow of individual particles.  A continuum treatment for the particle phase within a CFD framework is capable of simulating larger-scale processes yet requires constitutive models to describe averaged quantities associated with particle-particle and particle-fluid interactions.  Granular kinetic theory well describes these interactions in dilute and dense-phase collisional flow although this theory is typically restricted to monodisperse, spherical particles. This presentation will outline the development of constitutive models for the collisional dissipation rate and the particle-phase stress in granular kinetic theory for particle mixtures that are comprised of non-spherical grains which are described (within DEM) either as perfect cylinders or disks of varying aspect ratio or described using a linked and overlapping sphere approach.  This presentation will include DEM modeling of rigid and flexible non-spherical particles via a bonded particle model incorporating normal and shear forces as well as bending and torsional moments.  The model also allows for breakage of the non-spherical particles during impact with walls, under compression, and in agitated mixers.

Jennifer Sinclair Curtis is Distinguished Professor of Chemical Engineering and Dean of the College of Engineering at University of California, Davis.  She is a Fellow of AAAS, AIChE and ASEE. Professor Curtis is a recipient of a Fulbright Senior Research Scholar Award, AIChE's Thomas-Baron Award in Fluid-Particle Systems, the AIChE’s Fluidization Lectureship Award, the American Society of Engineering Education's Chemical Engineering Lectureship Award, the Eminent Overseas Lectureship Award by the Institution of Engineers in Australia, ASEE's Sharon Keillor Award for Women in Engineering, and the NSF Presidential Young Investigator Award.  Professor Curtis received a B.S. in Chemical Engineering from Purdue University (1983) and a PhD in Chemical Engineering from Princeton University (1989). Professor Curtis’ particulate flow models have been extensively adopted by both commercial and open source computational fluid dynamics (CFD) software packages.