2,987 research outputs found
Non-locality in Granular Flow: Phenomenology and Modeling Approaches
No full text© Copyright © 2019 Kamrin. This paper reviews the emergence of non-local flow phenomena in granular materials and discusses a range of models that have been proposed to integrate an intrinsic length-scale into granular rheology. The frameworks discussed include micro-polar modeling, kinetic theory, three particular order-parameter-based models, and strongly non-local integral-based models. An extensive commentary is included discussing the current capabilities of these existing models as well as their implementational ease, physical motivation, and breadth of predictive ability
Ken Friedenreich Interview
No full textThis interview is an oral history conducted by Linfield College student Camille Weber with Ken Friedenreich. The interview took place at the Jereld R. Nicholson Library at Linfield College on October 16, 2015.
Ken Friedenreich is an author who has written about Oregon wine and its history. The interview includes how he got interested in wine, what it\u27s like to write about wine for a living, the effects that prohibition had on Oregon, and advice for people new to wine
Microscopic Description of the Granular Fluidity Field in Nonlocal Flow Modeling
No full textA recent granular rheology based on an implicit "granular fluidity" field has been shown to quantitatively predict many nonlocal phenomena. However, the physical nature of the field has not been identified. Here, the granular fluidity is found to be a kinematic variable given by the velocity fluctuation and packing fraction. This is verified with many discrete element simulations, which show that the operational fluidity definition, solutions of the fluidity model, and the proposed microscopic formula all agree. Kinetic theoretical and Eyring-like explanations shed insight into the obtained form.Natioanal Science Foundation (U.S.) (Grant CBET-1253228
Simulation technique for slurries interacting with moving parts and deformable solids with applications
No full textA numerical method for particle-laden fluids interacting with a deformable solid domain and mobile rigid parts is proposed and implemented in a full engineering system. The fluid domain is modeled with a lattice Boltzmann representation, the particles and rigid parts are modeled with a discrete element representation, and the deformable solid domain is modeled using a Lagrangian mesh. The main issue of this work, since separately each of these methods is a mature tool, is to develop coupling and model-reduction approaches in order to efficiently simulate coupled problems of this nature, as in various geological and engineering applications. The lattice Boltzmann method incorporates a large eddy simulation technique using the Smagorinsky turbulence model. The discrete element method incorporates spherical and polyhedral particles for stiff contact interactions. A neo-Hookean hyperelastic model is used for the deformable solid. We provide a detailed description of how to couple the three solvers within a unified algorithm. The technique we propose for rubber modeling/coupling exploits a simplification that prevents having to solve a finite-element problem at each time step. We also developed a technique to reduce the domain size of the full system by replacing certain zones with quasi-analytic solutions, which act as effective boundary conditions for the lattice Boltzmann method. The major ingredients of the routine are separately validated. To demonstrate the coupled method in full, we simulate slurry flows in two kinds of piston valve geometries. The dynamics of the valve and slurry are studied and reported over a large range of input parameters.
Keywords
Discrete elements method Lattice Boltzmann Fluid–particle interaction Smagorinsky turbulence model Hyperelastic model Neo-Hookean elastic rubber modelUnited States. Army Research Office (grant W911 NF-15-1-0598)Schlumberger Limite
Some exact properties of the effective slip over surfaces with hydrophobic patternings
No full textShear flows of viscous fluid layers over nonuniformly hydrophobic surfaces are characterized in the far-field by an effective slip velocity, which relates to the applied stress through some mobility tensor characterizing the surface. Here, we identify two methods to determine the mobility tensor for flat surfaces with arbitrary slip-length variations. A family of “Cross Flow Identities” is then analyzed, which equate mobility components of different unidirectional patternings. We also calculate an analytical mobility solution for a family of continuously varying patterns. We validate the results numerically and discuss implications in various limits.MIT-France Progra
Soft catenaries
No full textUsing the classical catenary as a motivating example, we use slender-body theory to derive a general theory for thin filaments of arbitrary rheology undergoing large combined stretching and bending, which correctly accounts for the nonlinear geometry of deformation and uses integrated state variables to properly represent the complete deformation state. We test the theory for soft catenaries made of a Maxwell fluid and an elastic yield-stress fluid using a combination of asymptotic and numerical analyses to analyse the dynamics of transient sagging and arrest. We validate our results against three-dimensional finite element simulations of drooping catenaries, and show that our minimal models are easier and faster to solve, can capture all the salient behaviours of the full three-dimensional solution, and provide physical insights into the basic mechanisms involved.National Science Foundation (U.S.). Mathematical Sciences Postdoctoral Research Fellowship
Event Invitation: An Evening with Dr. Ken Robinson
No full textInvitation:
Guest speaker, Dr. Ken Robinson, author of “Out of Our Minds: Learning to be Creative, ” will speak on the importance of arts, the development of creativity, education, and the economy. And, introducing the inaugural DaVinci Scholars Awards program
Oral history interview with Ken Hada
No full textKen Hada, author and professor, talks about his upbringing as a minister's son and shares how he became interested in writing and in poetry. He recalls submitting his first two poems for publication and having them accepted. Hada explains his creative process, the challenge of self-identifying as a writer, and co-founding the Scissortail Creative Writing Festival in Ada, Oklahoma. He also discusses a few of his projects, including writing vignettes to go along with his brother's paintings of the Arkansas River and his book Bring an Extry Mule.The Deep Roots: Oklahoma Authors Collection is a series of interviews with authors who discuss their lives, work, and creative processes
Ken Knight
No full textPhotograph - Ken Knight at Nancy Appleby's home, Christmas 1986. Athabasca, Albert
Career Spotlight: Ken Abdo, Esq.
No full textAn interview with Ken Abdo. He is a partner at the law firm of Fox Rothschild LLP. Spanning forty years, he has extensive experience serving as legal counsel to artists, creators, and businesses in the music and entertainment industries. He is a prolific author and lecturer on music and entertainment law matters. Harnessing his earlier years of experience as a musician, entertainer, and adjunct professor of entertainment law, Ken’s career has been a storied ride working with developing, established, legacy, and estates of music artists. He now represents both buyers and sellers of music artist recording and publishing catalogs. His commitment to advocacy has vaulted him to national and international leadership positions with The Recording Academy, the American Bar Association, The International Association of Entertainment Lawyers, and other organizations
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