Colloquium-Physics Department

From the venue:

Title: Flashing Lights in Speeding Grains and "Catch me if you can!"

Abstract: Flowing granular materials arise everywhere around us, in industry from pharmaceutical processes to bulk good transport lines, and in nature from snow avalanches to captivating dune fields. In geophysical mass flows encountered in nature, we have an interesting interplay between microscale (grain-grain contacts) and macroscale processes (continuum behavior). In order to understand critical macroscale processes such as slope stability, creep of a hillslope and failure of a dam, we need to be able to visualize and characterize the microscale interactions between individual grains and layers. In this talk, I will introduce some of the research that we have conducted in my research group in the past few years, with a focus on laboratory experiments of avalanches and sand dunes.

Bio: Associate Professor Nathalie Vriend joined the University of Colorado Boulder in 2022. Prior to CU Boulder, she spent a 12-year period in the United Kingdom at the University of Cambridge in the Department of Applied Mathematics and Theoretical Physics (DAMTP) and later at the BP Institute. Dr. Vriend earned her ingenieurs (B.Sc. + M.Sc.) degree in Mechanical Engineering (2004) from the University of Twente, The Netherlands and her M.Sc. and Ph.D. degrees from the California Institute of Technology, USA. Dr. Vriend leads the Granular Flow Laboratory at CU Boulder and is a 2023 Moore Foundation Experiment Physics Initiative awardee. She is an expert in performing detailed laboratory experiments and targeted field work involving particulate flows such as sand and snow. In addition, she also employs numerical simulations and theoretical modelling to complement observations, often in collaboration with scientists from multidisciplinary fields. She has active projects in granular rheology and avalanching, and dune structure and migration. In the past she worked on the dynamics of real snow avalanches, singing sand dunes, silo honking, and seismic wave propagation.