White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Acoustic solutions to the particle mixing problem in aqueous dispersions

Hazlehurst, Thomas Alexander (2015) Acoustic solutions to the particle mixing problem in aqueous dispersions. PhD thesis, University of Leeds.

[img]
Preview
Text (PhD Thesis)
Hazlehurst_TA_Applied_Mathematics_PhD_2015.pdf - Final eThesis - complete (pdf)
Available under License Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales.

Download (21Mb) | Preview

Abstract

Colloidal dispersions are found in many modern product formulation processes, and one of the problems commonly occurring in these processes is characterising the particles within these systems. The existing theories for predicting acoustic scattering in these systems do not fully account for the interactions between neighbouring particles. Most importantly they do not account for the thermal interactions in thermoacoustic scattering. In this thesis I develop an asymptotic solution in the small wave number limit to the multiple scattering problem. This is done by considering the thermoacoustic field interaction between two different sized particles close together, and applying this to a pair distribution probability function, giving an extra term in the far field scattering calculations. This provides a method of predicting attenuation in mono- and bi-disperse colloids, especially for those of higher concentrations. This theory is compared to attenuation experimental data for a number of different colloidal systems, mono- and bi-disperse of increasing concentrations, where the thermal field overlap between particles is more prominent. Comparing these experiments with the new two particle thermoacoustic scattering theory give more consistent results than previous theories for volume concentrations up to 30%. Further work, as part of a CASE studentship, on sedimentation detection in pipe flow using by monitoring the behaviour of pulses of ultrasound is also presented in this thesis.

Item Type: Thesis (PhD)
Keywords: Acoustic scattering, ultrasound, Helmholtz, multiple scattering
Academic Units: The University of Leeds > Faculty of Maths and Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds)
Identification Number/EthosID: uk.bl.ethos.678065
Depositing User: Dr Thomas A Hazlehurst
Date Deposited: 27 Jan 2016 13:30
Last Modified: 26 Apr 2016 15:44
URI: http://etheses.whiterose.ac.uk/id/eprint/11646

You do not need to contact us to get a copy of this thesis. Please use the 'Download' link(s) above to get a copy.
You can contact us about this thesis. If you need to make a general enquiry, please see the Contact us page.

Actions (repository staff only: login required)