Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.560753
Title: Studies of liquid-liquid two-phase flows using laser-based methods
Author: Morgan, Rhys Gareth
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2012
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Abstract:
The research described in this thesis has been focused on the detailed investigation of horizontal co-current liquid-liquid two-phase flows. The experiments were carried out in channels of square and circular cross section and involved the use of two immiscible liquids of matched refractive index; namely an oil (Exxol™D80) and a 81.7 wt% glycerol-water solution. The experiments were carried out in a refurbished liquid-liquid flow facility (TOWER) and the focus was on examining the flows using high-speed laser-based visualisation methods which allowed both qualitative evaluation of the nature of the flows (i.e. the flow patterns) and quantitative measurements of parameters such as drop size and velocity distribution. The laser-based techniques used included Planar Laser Induced Fluorescence (PLIF), Particle Tracking Velocimetry (PTV) and Particle Image Velocimetry (PIV). Using these techniques, it was possible to obtain high spatial and temporal resolution measurements of velocity and phase distribution of liquid-liquid flows which enabled the detailed diagnostic inspection to an extent that has not been previously possible. 144 experiments were carried out in three experimental campaigns. In the first campaign, a square cross section channel was used in order to avoid image distortion by the channel walls. In the second and third campaigns, a circular tube was employed and a graticule correction method was used to correct the distortion to the PLIF and PTV/PIV images which occurs when the circular cross-section visualisation cell is used. In the two circular tube experiments, two methods of injection of the phases were used: (1) the heavier (glycerol solution) phase was injected in its natural location at the bottom of the channel, and (2) in the second case the heavier phase was injected at the top of the channel. The PLIF images gave a clear indication of the distribution of the phases at the channel centre line and have been used qualitatively in obtaining information about the flow patterns occurring. The PLIF images have also been used quantitatively in generating data on phase distribution, insitu phase fraction, interface level and drop size distribution. Much of the data on in-situ phase fraction and interface level fits well with a simple laminar-laminar stratified flow model. The PTV/PIV method provided extensive data on velocity profiles; in the lower (aqueous glycerol solution) phase, the profile usually showed the curved shape characteristic of laminar flow and in the upper (Exxol™D80) phase, the velocity profile often showed the flattened form characteristic of turbulent flow.
Supervisor: Hewitt, Geoffrey ; Markides, Christos Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.560753  DOI: Not available
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