Fluids-related department seminar: Justin Burton, Emory

Justin Burton from Emory University will be visiting to give the Department of Earth Sciences seminar on November 6 (Willamette 110, 4-5 pm). Justin does all kinds of neat research at the interface of granular materials and fluids. He will be talking to us about jamming in icebergs.

Tidewater glaciers and the dynamics of giant icebergs: granular physics on the geophysical scale

Accelerated warming in the past few decades has led to a dramatic increase in glacial activity. This is perhaps most apparent in tidewater glacial fjords, where gravitational flows from ice sheets are focused into narrow channels of thick, fast-flowing ice which terminate into the ocean. The result is a complex system involving both melting and iceberg calving (fracture) which has a direct impact on the Earth’s climate and sea level rise. However, there are numerous inherent difficulties in collecting field data from remote, ice-choked fjords. To address this, we use a laboratory scale model to measure aspects of tidewater glaciers which are not observable in nature. Our model has helped to uncover the source of glacial earthquakes, where floating, cubic kilometer scaled icebergs capsize due to gravitational instability, and temporarily reverse the velocity of the glacier. We have also investigated the granular nature of ice mélange, which is an enormous collection of broken icebergs and sea ice that sits in front of the largest glaciers in Greenland.  The forces generated by the glacier slowly pushing the jammed mélange can be large enough to influence the calving of new icebergs, and the flow coherence of ice melange can be used as a predictor of impending calving events. This is perhaps the world’s largest granular material, and we have shown that the understanding of granular materials and rheology developed for laboratory-scale grains can also be applied here.

Host: Leif Karlstrom, leif@uoregon.edu

 

Two special fluids seminars this week!

We have two fluids seminars this week:

1. Tuesday May 21 we have Stephen Solovitz visiting from Washington State University (Vancouver). Stephen works on a variety of fluid/solid interactions with a novel experimental approach. He will be talking at the Volcanology Seminar in the Vis Lab in the Science Library, 1-2 pm.

Fluid Dynamics Laboratory

Please contact Josef Dufek to meet with Stephen: jdufek@uoregon.edu

2. Friday May 24 we have Yang Liao visiting from Woods Hole Oceanographic Institution. Yang develops theoretical and numerical methods for unsteady flows associated with volcanoes. She will be speaking about poroelasticity and magma chamber dynamics, 3-4 pm in the ITS conference room Willamette 472.

https://directory.whoi.edu/profile/yliao/

Please contact Leif Karlstrom to meet with Yang: leif@uoregon.edu

 

Fluids seminar series, Spring 2019!

There will be three special Interdisciplinary Fluids Seminars in Spring 2019, sponsored by CAS. Talks will be Fridays in the Institute for Theoretical Science conference room, 472 Willamette Hall, at 3 pm unless otherwise noted.

The first speaker will be next week, April 5, David Bercovici from Yale University. He will talk about “Mushy magnetohydrodynamics in freezing planetary cores”.

Check the 2019 Seminar schedule page for other talks. Hope to see you there!

 

 

GEOL 454/554 offered Winter 2019

See here a nice time-lapse of viscous and turbulent flow (lava and atmosphere) from the 2018 eruption of Kilauea.


Now that you’re interested… Fluid Dynamics is now officially part of the UO course catalog as GEOL 454/554!

It will be taught Winter 2019 by Leif Karlstrom, MW from 10-11:50 AM in Cascade 202. Email questions to: leif@uoregon.edu

UO Catalog description:

This course is an introduction to fluid dynamics, a mature branch of physics that is both a constant presence in everyday life and a defining element of current research across the physical and biological sciences. Processes as diverse as planet formation, volcanic eruptions, design of concert halls, and jellyfish swimming all involve fluid dynamics at a basic level. We will discuss the continuum mechanics description of fluid motion, focusing on the Navier-Stokes equations of motion as well as common simplified limits and extensions. Examples will be drawn from Earth and Planetary Science, Biology, and Physics.

 

[embeddoc url=”https://blogs.uoregon.edu/fluids/files/2018/11/Fluid_Dynamics_Syllabus_2019-1upazic.pdf” download=”all” viewer=”google” ]

Graduate Fluids course in Earth Sciences this Spring

Hello fluids enthusiasts!

I will be offering GEOL 410/510: Fluid Dynamics this Spring quarter (MW 12:00-13:50), covering the continuum mechanics theory of fluid motion and applications. The course is presented in a general way, appropriate for advanced undergraduate and graduate students in Earth Sciences, Physics, Chemistry, Biology and Geography.

The attached syllabus provides a detailed description of the course, including textbook, objectives and tentative schedule. A working knowledge of vector calculus and differential equations is desirable, as are basic programming skills. Please contact me if you have questions, and please disseminate to other interested parties on campus!


Leif Karlstrom
leif@uoregon.edu
Department of Earth Sciences
http://pages.uoregon.edu/leif/

[embeddoc url=”https://blogs.uoregon.edu/fluids/files/2017/02/GEOL410_510_Fluid_Dynamics_2017-2jokpra.pdf” download=”all” viewer=”google”]

Seminar this week, David Furbish from Vanderbilt

Fluid Dynamics Seminar: David Furbish, Vanderbilt University

Title: Flow and bedform dynamics in rivers and experiments: The bed instability problem

Date: Wednesday, June 1, 2016

Time: 1 pm
Location: ITS Conference Room, 472 Willamette Hall

David Furbish is a professor at Vanderbilt University in Earth and Environmental Science. His work involves the application of fluid mechanics and statistical mechanics to problems in geomorphology, hydrology, and ecology. This work combines theoretical, experimental, computational and field-based components aimed at understanding the dynamics of Earth surface systems spanning human to geomorphic time scales.

Summary:

A nice philosophical introduction to David’s approach to science may be found on his website:

“…in learning how to describe the behavior of mechanical systems, mostly we are initially exposed to deterministic examples. We study Newton’s laws as these pertain to simple particle systems, and then move on to the behavior of solids and fluids treated as continuous materials. The formalism is unambiguous, and describing the behavior of a well constrained system is in principle straightforward. Indeed, much (although not all) of the legacy of geophysics resides in the determinism of continuum mechanics. Perhaps it is therefore natural that we might envision that a mechanistic description of the behavior of a system implies that such a description ought to be, or perhaps only can be, a deterministic one. Such a perception represents a lost opportunity. The most elegant counterpoint example is the field of classical statistical mechanics — devoted specifically to the probabilistic (i.e., non-deterministic) treatment of the behavior of gas particle systems in order to justify the principles of thermodynamics — yet which is no less mechanical in its conceptualization of this behavior than, say, the application of Newton’s laws to the behavior of a deterministic system consisting of the interactions of a few billiard balls or the players of the solar system, or involving the motion of a Newtonian fluid subject to specific initial and boundary conditions.”
Please contact Leif Karlstrom if you would like to schedule a meeting with David.

This weeks seminar, James Strother from Oregon State University


Who: Jim Strother from the Dept. of integrative biology at OSU

When/where: Wed. May 11 at 1 pm in the ITS Conference Room, 472 Willamette Hall

Title: How to breathe underwater: the fluid dynamics of ventilation in fishes

More on Jim’s research on his website:

The Strother Lab examines how physiology, biomechanics, and neurobiology shape the interaction of aquatic animals with their environment.

Our current research is focused on understanding the mechanisms of respiratory exchange, using zebrafish as a model system. Respiratory exchange is a highly complex and multiscale process governed by the fluid dynamics of ventilation, the diffusion of solutes through the respiratory membranes, the transport of solutes by the cardiovascular system, and sensing and regulation by the nervous system. To disentangle these dynamics our lab utilizes a wide range of methods, including imaging, in vivo physiological experiments, computational modeling, and behavioral studies.

Hope to see you there!

 

Seminar this week, Mimi Koehl from UC Berkeley – note change of location

Fluid Dynamics Seminar: Mimi Koehl, University of California at Berkeley

Title: Swimming and crawling in a turbulent world

Date: Wednesday, May 4, 2016

Time: 1 pm
Location: 331 Klamath (note change from usual location)

Mimi Koehl is a professor at UC Berkeley in integrative biology, a member of the National Academy of Sciences, fellow of the AAAS, and a recipient of a McArthur Award.

Summary:

“I study the physics of how organisms interact with each other and their environments. My goal is to elucidate basic physical rules that can be applied to different kinds of organisms about how body structure affects mechanical function in nature. I combine techniques from fluid and solid mechanics with those from biology and ecology to do experiments in the field as well as in the laboratory.

We have been using this approach to address a variety of questions, including how microscopic creatures swim and capture food in turbulent water flow; how marine larvae recruit into benthic habitats; how being multi-cellular affects swimming, feeding, and predator avoidance in protozoan ancestors of animals; how morphology affects aerodynamic performance of extinct ancestors of flying insects and birds; how wave-battered marine organisms avoid being washed away; how hydrostatic organisms change shape and move through their habitats; and how suspension-feeding aquatic animals capture particles and how olfactory antennae catch odors from water moving around them.”

More information: Mimi’s website

Please contact Kelly Sutherland if you would like to schedule a meeting with Mimi during her visit.

http://pages.uoregon.edu/ksuth

ITS/Fluids seminar next week: Evan Variano, UC Berkeley

Fluid Dynamics/ITS Seminar: Evan Variano, University of California at Berkeley

(this is a regularly-scheduled Institute for Theoretical Science seminar)

Title: Turbulent transport of non-spherical suspended particles: particle shape, size and rotation

Date: Tuesday, April 26, 2016

Time: 4 pm to 5 pm
Location: ITS Conference Room, 472 Willamette Hall

Evan Variano is an associate professor at UC Berkeley in the Department of Civil and Environmental Engineering. His research interests span transport and mixing in flows inspired by environmental processes, often at the intersection of Ecology and Fluid dynamics.

Abstract:

Natural particles suspended in water are often non-spherical. We explore the ways in which particle size and shape affects particle motion, focusing on particle parameters relevant for plankton, sediment aggregates, or autonomous vehicles.  We find that shape has only a very weak effect on particle angular velocity, which is a quantity calculated with respect the global reference frame (i.e. east/north/up). If we analyze rotation in a particle’s local frame (i.e. the particle’s principle axes of rotation), then particle shape has a strong effect on rotation. In the local frame, rotation is described by two components: tumbling and spinning. We find that rod-shaped particles spin more than they tumble, and we find that disc-shaped particles tumble more than they spin. These preferential rotations, as well as total angular velocity, decrease with increasing particle size.  Such behavior is indicative of how particles respond to the directional influence of vortex tubes in turbulence, and such response has implications for particle motion other than rotation. Understanding particle alignment is relevant for predicting particle-particle collision rates, particle-wall collision rates, and the shear-driven breakup of aggregates. We discuss these briefly in the context of what can be concluded from the rotation data discussed above.

More information: Evan’s website.

Please email Leif Karlstrom if you would like to schedule a meeting with Evan during his visit.

abstract_Variano_2016(1)

 

Fluids/ITS seminar next week: Josef Dufek from Georgia Tech

Fluid Dynamics/ITS Seminar: Josef Dufek, Geogia Institute of Technology

Title: The fluid dynamics of explosive volcanic eruptions: Multiscale flow in eruptive plumes and pyroclastic density currents

Date: Wednesday, April 13, 2016

Time: 1 pm to 2 pm
Location: ITS Conference Room, 472 Willamette Hall

Josef Dufek is an associate professor at Georgia Tech in the School of and Planetary Sciences. He is a Blanchard-Miliken Fellow and recipient of the American Geophysical Union Macelwane Medal in 2012.  He has wide-ranging fluids interests that span basic multiphase granular flows, numerical methods for multiphase turbulent flow, and analog laboratory experiments.

Abstract:

Explosive volcanic eruptions produce flows that span a range of fluid dynamic regimes, and the ability of these flows to transform from one regime to another plays a significant role in their ability to modify the crust, landscape and atmosphere and produce hazardous conditions. A growing body of numerical, experimental and observational evidence indicates that homogeneity in particle-fluid systems is the exception rather than the rule. Particle segregation is not a passive process, and can feedback in the rheology of granular mixtures controlling the mixing and run-out distance of particle-laden flows. The aim of this talk is to discuss progress in using fluid and granular mechanics to understand the multiphase transport physics of volcanic flows, and demonstrate how an understanding of the dynamics of these high-energy, end member flows yields insight into a range of other geophysical flow types.

I will discuss the use of multiphase models in addressing the different scales of fluid motion in volcanic multiphase flow as well as how they can provide a platform to integrate microphysical, analogue experiments and observational constraints. Microphysical experiments can provide the necessary closure for statistical mechanics based models, and provide a way to examine grain-scale processes in a probabilistic manner. Such small-scale processes can dramatically alter the flow dynamics. One of the primary goals and utilities of this combined approach is that it enables comparison with diverse datasets, integrating previously disparate observations. In this talk I will illustrate eruptive flow styles that cover very different dynamic ranges and observation types, and in particular discuss the fluid dynamics of near vent entrainment and pyroclastic density currents. In each case, laboratory experiments, numerical modeling results and observations will be combined to decipher physical processes. The insight from these approaches will also be discussed in the context of future terrestrial measurements as well as to give insight into planetary processes where conditions may have differed considerably from those on contemporary Earth.

More information: Joe’s website.

Hope to see you there!

Dufek Seminar Flyer 4.13.16

Fluids Seminar next week: Grae Worster, Cambridge University

Fluid Dynamics/ITS Seminar: Grae Worster, University of Cambridge

Title: Collapsing ice sheets

Date: Wednesday, March 9, 2016

Time: 1:30pm to 2:30pm
Location: ITS Conference Room, 472 Willamette Hall

M.G. Worster is a professor in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge and serves as the current editor of the Journal of Fluid Mechanics.

Abstract: Most of the West Antarctic Ice Sheet (WAIS) sits on bedrock that is one to two kilometres below sea level. Its weight causes the ice sheet to flow outwards towards the ocean, thinning as it goes until it is thin enough to float on the ocean as an ice shelf before it ultimately breaks up into icebergs. Some areas of the WAIS have been accelerating in recent years, as the point at which the sheet begins to float recedes, and this contributes to the rise in global sea level. I shall describe some recent analogue laboratory experiments and associated mathematical models that describe and quantify the fundamental dynamical controls on ice sheets that terminate in the ocean, focusing particularly on the role that floating ice shelves play in buttressing the ice sheet against collapse.

More information: http://www.damtp.cam.ac.uk/people/m.g.worster/

Spring course on Non-equilibrium Statistical Mechanics

Marina Guenza is offering a course that should be of interest to a fluids-minded audience this Spring, through the Chemistry department. Here are the details:

CH446/546
time:11-11:50  twrf
location: 107 Klamath
Prerequisite: CH 413 (undergraduate physical chemistry) or equivalent.
This is a course for advanced undergraduate and graduate students, interested in modeling the dynamics of molecular and living systems (biophysics). It is a rigorous course in non-equilibrium statistical mechanics, for systems close to equilibrium.
It provides the basic mathematical and physical background to represent the motion of systems of biological interest (from protein folding, to self-assembly, to brownian ratchets, to directed diffusion etc.).
Contact Marina Guenza for more information: mguenza@uoregon.edu

Spring course on Transport Processes, 2 credits, Tue/Thurs, 1-2pm

Dear Fluids aficionados,

This spring, visiting Fellow David Furbish will teach a seminar-style course with applications to magma, crystallization, rivers, glaciers, and granular flows, among others (see syllabus for details).

Title: Transport Processes in Earth and Environmental Systems

Tues/Thurs, 1-2pm, 200 Cascade Hall

2 credits, P/NP

The reading for week 1 is: “The Unreasonable Effectiveness of Mathematics in the Natural Sciences” by E. Wigner, 1960, Communications of Pure and Applied Mathematics, v. 8, p 1-14. LINK

David is the author of:

Furbish, D. J. (1997), Fluid Physics in Geology, Oxford University Press.

Furbish, D.J. (forthcoming), The Probabilistic Analysis of Sediment Transport, Oxford University Press.

He is also going to be a speaker in the Fluids seminar series on June 1.

https://my.vanderbilt.edu/davidjonfurbish/