|COOKIES: By using this website you agree that we can place Google Analytics Cookies on your device for performance monitoring.|
Particle size segregation and spontaneous levee formation in geophysical mass flows
If you have a question about this talk, please contact Dr Ed Brambley.
Hazardous geophysical mass flows, such as snow avalanches, debris-flows and pyroclastic flows, often spontaneously develop large particle rich levees that channelize the flow and enhance their run-out. Measurements of the surface velocity near an advancing flow front have been made at the United States Geological Survey (USGS) debris-flow flume, where 10m$^3$ of water saturated sand and gravel are allowed to flow down an 80m chute onto a run-out pad. In the run-out phase the flow front is approximately invariant in shape and advances at almost constant speed. By tracking the motion of surface tracers and using a simple kinematic model, it was possible to infer bulk motion as incoming material is sheared towards the front, over-run and shouldered to the side. At the heart of the levee formation process is a subtle segregation-mobility feedback effect. Simple models for particle segregation and the depth-averaged motion of granular avalanches are described and one of the first attempts is made to couple these two types of models together. This process proves to be non-trivial, yielding considerable complexity as well as pathologies that require additional physics to be included.
This talk is part of the Fluid Mechanics (DAMTP) series.
This talk is included in these lists:
Note that ex-directory lists are not shown.
Other listsConspiracy and Democracy Project Wolfson College Lunchtime Seminar Series - Wednesdays of Full Term International Cafe Scientifique
Other talksAnatomical dissection as a performance practice How to read the Confessions of Augustine Some dynamics of brine and compressible vapour flows in permeable conduits Dissecting computations in the dopamine reward circuit Mass spectrometry Is the coefficient of restitution energentically consistent?