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You searched for +publisher:"University of North Carolina" +contributor:("Falcon, Claudia"). One record found.

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University of North Carolina

1. Falcon, Claudia. Entrainment dominated effects in the long residence times of solid spheres settling in sharply stratified miscible viscous fluids.

Degree: Mathematics, 2016, University of North Carolina

This dissertation presents results on the effects of sharp density variations in the dynamics of settling spheres in viscous-dominated regimes by a combination of experimental, analytical, and numerical tools. Particles settling through naturally-stratified fluids, such as the ocean and the atmosphere, affect many aspects of life, from air quality and pollution clearing times to the formation of thin aggregate layers in the upper ocean. In this thesis, we develop an understanding of the dynamics that affect these problems by studying the behavior of a sphere falling under gravity through a two-layer fluid. We have found that the sphere slows down dramatically as it passes through the density transition. In this system, we demonstrate the importance of the entrained fluid to the delayed settling of the particle due to its added buoyancy force. In particular, we compare long residence times at the interface rivaling the ones observed for porous spheres and marine snow - aggregates that occur naturally in the ocean- in similar configurations. We call these cases the entrainment dominated regimes, where diffusion of salt could play an active role and it is therefore needed in the modeling. The developed first principle model is a highly coupled system that captures the most significant aspects of settling in a sharp two-layer fluid. We discuss previously implemented approximations and new experimental regimes where the approximation is no longer valid. The asymptotic approaches and exact solutions for the sphere exterior problem of the Stokes equations will be compared in a parametric study of relevance for experiments. The region of validity for the approximations, the full theory agreement, and the possible need to include diffusion in the entrainment dominated regimes will be discussed and explained. The single particle theory further sheds light in the settling rates of marine aggregates falling through sharp density transitions, and how this ultimately affects marine carbon cycling. In addition to solid spheres, we have examined porous, and drilled spheres , obtaining range of parameters that enhance the residence time at the interface. We have also investigated this phenomenon extensively through experiments by observing clouds of solid particles as they settle through a sharply stratified water column. Advisors/Committee Members: Falcon, Claudia, Camassa, Roberto, McLaughlin, Richard, Adalsteinsson, David, Forest, M. Gregory, Miller, Laura.

Subjects/Keywords: College of Arts and Sciences; Department of Mathematics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Falcon, C. (2016). Entrainment dominated effects in the long residence times of solid spheres settling in sharply stratified miscible viscous fluids. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:7fc69ed1-8468-4c8e-a16e-da494daecb02

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Falcon, Claudia. “Entrainment dominated effects in the long residence times of solid spheres settling in sharply stratified miscible viscous fluids.” 2016. Thesis, University of North Carolina. Accessed December 02, 2020. https://cdr.lib.unc.edu/record/uuid:7fc69ed1-8468-4c8e-a16e-da494daecb02.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Falcon, Claudia. “Entrainment dominated effects in the long residence times of solid spheres settling in sharply stratified miscible viscous fluids.” 2016. Web. 02 Dec 2020.

Vancouver:

Falcon C. Entrainment dominated effects in the long residence times of solid spheres settling in sharply stratified miscible viscous fluids. [Internet] [Thesis]. University of North Carolina; 2016. [cited 2020 Dec 02]. Available from: https://cdr.lib.unc.edu/record/uuid:7fc69ed1-8468-4c8e-a16e-da494daecb02.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Falcon C. Entrainment dominated effects in the long residence times of solid spheres settling in sharply stratified miscible viscous fluids. [Thesis]. University of North Carolina; 2016. Available from: https://cdr.lib.unc.edu/record/uuid:7fc69ed1-8468-4c8e-a16e-da494daecb02

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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