Headshot Vriend
Associate Professor • Thermo Fluid Sciences, Mechanics of Materials
Mechanical Engineering

Office Location: ECME 222
Lab Location: ECNW 1B90

Research Interests:

Imaging, Measuring and Modelling Granular flows in the Environment.

Dr. Vriend leads the Granular Flow Laboratory. 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.

Societal Impact:

Climate change impacts weather patterns and meteorological long-term data and subsequently erosion rates in deserts. Desertification is a global concern and mobile hyper-arid desert dunes threaten settlements and infrastructure of as many as one billion people worldwide. To effectively mitigate the hazard for downwind communities and infrastructure, we need to understand the dynamics of their evolution, from the growth of a bedform to the steady-state processes of a mature dune.

Flowing granular materials arise everywhere around us, in industry from pharmaceutical processes to bulk goods transport lines, and in nature from snow avalanches to devastating landslides. To mitigate industrial economic losses and reduce hazards of naturally occurring flows, we need to be able to measure and model static and flowing granular materials, with transitions strongly depending on the spatial boundary conditions of the flow, external forcing, and time-dependent starting and stopping phenomena.

Research group dynamics:

In my research group, I promote and advance "Be A JEDI" (*): Belonging, Accessibility, Justice, Equity, Diversity and Inclusion. To me, this means that I want to create a welcoming environment for you (as my future group member) where you can reach your full potential and feel part of our crew. I highly value a balanced integration of work, family and private time: I am aware of the importance of this due to extended periods of leave and a non-linear career path I have taken, and I want to meet your personal needs such that you can reach your full potential in your professional research career. Please contact me directly if you have any questions, considerations or concerns.

(*) This all-inclusive term has gained popularity in the geoscience community in the past few years, driven by efforts from Vashan Wright, Brandon Jones and others.

Select Publications:
Supervised students and postdocs underlined

T. Dauxois, T. Peacock, P. Bauer, C.P. Caulfield, C. Cenedese, C. Gorle, G. Haller, G.N. Ivey, P.F. Linden, E. Meiburg, N. Pinardi, A.A. Sepp Neves, N.M. Vriend, A. Woods, Confronting Grand Challenges in Environmental Fluid Dynamics (2021), Physical Review Fluids 6, 020501.

K.A. Bacik, S. Lovett, C.P. Caulfield, N.M. Vriend, “Wake-induced long range dune-dune repulsion” (2020), Physical Review Letters 124 (editor’s choice), 054501.

A.L. Thomas, N.M. Vriend, Photoelastic study of dense granular free-surface flows” (2019), Phys. Rev. E 100, 012902.

M.I. Arran, N.M. Vriend, “Intermittency between avalanche regimes in granular media” (2018), Phys. Rev. E (rapid communication) 97, 060901(R)

N.M. Vriend, P.A. Jarvis, “Between a ripple and a dune” (2018), Nature Physics (invited) 14 (7), 741 - 742.

M.L. Hunt, N.M. Vriend, “Booming Sand Dunes” (2010), Annual Review of Earth and Planetary Sciences 38, 281-301.

Background:

Associate Professor Nathalie Vriend joined the University of Colorado Boulder in 2022. Prior to CU Boulder, she spend a 12-year period in the United Kingdom at the University of Cambridge. After a short postdoctoral position (2010 – 2011) and holding a competitive personal postdoctoral fellowship (2011 – 2013) in the Department of Applied Mathematics and Theoretical Physics (DAMTP), she started her own research group. Between 2014 and 2022, Nathalie has been group leader and Royal Society Research Fellow, first as a Dorothy Hodgkin Research Fellow in DAMTP and from 2019 onwards as a University Research Fellow at the BP Institute, both at the University of Cambridge.

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. (2005, in Aeronautics) and Ph.D. degree (2010, in Mechanical Engineering and Geophysics) from the California Institute of Technology, USA.