Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.519257
Title: Modelling the micro-structure and hydraulic properties of sands
Author: Garcia Teijeiro, Xavier
Awarding Body: Imperial College London (University of London)
Current Institution: Imperial College London
Date of Award: 2007
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Abstract:
The main objective of this work is to model granular materials comprising particles of as pherical shape and investigate the effect of the grain shape on the hydraulic properties of the material. For this purpose, a Discrete Element Method code for clustered spheres was developed during the course of this work to simulate aspherical particles. The shape of the particles modelled mimics the morphology of real grains obtained from a shape library of real scanned particles for which development this thesis also contributed. The simulation tools are then used to construct models of real sands by simulating the settling under gravity and compaction of the grains. The hydraulic properties of the sand moels are then investigated via numerical simulations using two different approaches. First, we simulate low Reynolds numbers flow in granular packs using a Finite Element method within the Stokes flow approximation. Then we explore the applicability of the two-fluids approach to simulate fluid flow in the presence of solid obstacles and complex microstructures. By integrating the technologies developed during this work, it was possible to simulate the single phase flow in a wide range of Reynolds number in models of sand. The results obtained closely agree with available experimental data and empirical correlations for relatively clean and homogeneous sands. These results show that the hydraulic permeability can vary within a factor of two as a consequence of the particle shape. This indicates that for unconsolidated media the most important parameter with regards to fluid flow conductivity is the porosity.
Supervisor: Latham, John-Paul Sponsor: Rio Tinto ; Department of Earth Sciences and Engineering
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.519257  DOI: Not available
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