Head-on collisions of dense granular jets /

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Bibliographic Details
Author / Creator:Ellowitz, Jake, author.
Ann Arbor : ProQuest Dissertations & Theses, 2015
Description:1 electronic resource (42 pages)
Format: E-Resource Dissertations
Local Note:School code: 0330
URL for this record:http://pi.lib.uchicago.edu/1001/cat/bib/10773227
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Other authors / contributors:University of Chicago. degree granting institution.
Notes:Advisors: Wendy W. Zhang Committee members: Heinrich M. Jaeger; Sidney R. Nagel; Robert Rosner.
Dissertation Abstracts International, Volume: 77-02(E), Section: B.
Summary:When a dense stream of dry, non-cohesive grains hits a fixed target, a collimated sheet is ejected from the impact region, very similar to what happens for a stream of water. In this study, as a continuation of the investigation why such remarkably different incident fluids produce such similar ejecta, we use discrete particle simulations to collide two unequal-width granular jets head-on in two dimensions. In addition to the familiar coherent ejecta, we observe that the impact produces a far less familiar quasi-steady-state corresponding to a uniformly translating free surface and flow field. Upon repeating such impacts with multiple continuum fluid simulations, we show that this translational speed is controlled only by the total energy dissipation rate to the power 1.5 and is independent of the details of the jet composition. Our findings, together with those from impacts against fixed targets, challenge the principle of scattering in which material composition is inferred from observing the ejecta produced during impact.