Particle simulations via the discrete element method (DEM) have been widely used to model a range of pharmaceutical processes (material storage and transport, comminution, etc.). Simulations can enable detailed analysis and flow visualization and explore the effect of material properties and operating conditions. These insights can promote innovation and reducing inefficiencies, thus cutting costs associated with additional experimentation and scale-up studies.
Recent advances in particle models have significantly expanded the range of pharmaceutical systems and processes that can be described. Some of these advances include the modeling of particle mixes with wide variation in size, particle roughness, particle friction and particle cohesivity due to liquid bridging forces. Other model extensions include descriptions for particle aspericity that can also allow for particle breakage and flexibility. All of these complexities considerably affect the processing behavior of the particles. For example, surface moisture results in particle agglomeration, as is well known, but the particle aspect ratio determines the size and packing (solids volume fraction) of the agglomerates that are formed and the force required to convey or blend the particle mixture. And, when the solid volume fraction approaches the maximum packing density, the particle friction coefficient can be a more dominant factor than the liquid bridge force in determining the particle stress.
Jennifer Sinclair Curtis
University of California, Davis
Biography – Jennifer Sinclair Curtis
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, AIChE’s van Antwerpen 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. She was the first to partner with ANSYS Fluent to greatly expand the multi-phase simulation capability of that 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 CFD software package and the open-source CFD codes OpenFOAM and MFIX.