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Membrane emulsification is a technique which uses the pores of a microporous membrane to disperse one of two immiscible liquids, the disperse phase, into another liquid, the continuous phase, by applying pressure. The possible advantages of using this technique are that it is a low-shear, low-energy process capable, in theory, of producing an emulsion with a narrow droplet size. The main aim of this study was to provide a systematic analysis of membrane emulsification processes for the production of O/W emulsions using commercial available equipment and membranes. An experimental approach was adopted. Two methods of membrane emulsification were investigated. The first, dead-end membrane emulsification, used an adaptation of traditional membrane filtration equipment. Several membrane types were selected and investigated, including flat-sheet polymeric micro-and ultrafiltration membranes, and a ceramic microfiltration membrane. The second method, crossflow membrane emulsification, employed a hollow fibre ultrafiltration membrane. A standard emulsion formulation and experimental protocol for emulsion formation and characterisation was employed for all experimental work. Experimental investigations showed that O/W emulsions could be reproducibly produced with each membrane type, with emulsion characteristics related to membrane characteristics and operating conditions. For all membranes the results indicated that good quality emulsions with small droplet sizes and narrow size ranges were produced at slow disperse phase flowrates, usually at the lowest operating pressure possible, and moderate stirring at 600 rpm, or low crossflow velocities. An optimum set of operating conditions was most clearly identified for the polymeric microfiltration membranes. For comparison purposes, emulsions were produced using stirring only and by vortex mixing. Characterisation of the emulsions was undertaken using optical microscopy with image analysis and particle sizing techniques. Membrane characteristics were obtained using atomic force microscopy and scanning electron microscopy.

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Based on the theory of 'Double-Porosity', three-phase fluid flow in a fractured porous media has been formulated using continuity and equilibrium equations where displacement is also a primary unknown. Unlike previous models used for fractured media, the pressure of each fluid phase within the fracture network and porous rock has been considered to be coupled with the deformation of porous media. Also coupling between the fracture network and the porous rock is carried out using 'Transfer Function' or 'Leakage Term'. The derived equations are then discretised using 'Finite Element Method' where the displacements as well as pressure of fluids within matrix and fracture are primary unknowns. The resulting set of equations, is an implicit, fully coupled formulation which is capable of modelling three phase (Oil, Gas and Water) flow in a fractured reservoir where the deformation and consequent surface subsidence is of particular interest i.e. a case frequently encountered in petroleum engineering. In its extreme case, the presented formulation turns to the conventional one-phase models for heterogeneous porous media and by further simplification, the governing equations for ordinary single porosity models could be obtained. A computer code based on the mathematical model is developed and validated. Important aspects of the developed code, based on the double porosity theory, are presented together with several example problems. The model is also employed to solve a field scale example where the results are compared to those of ten other uncoupled models. As a genuine application of the present model, it is employed to solve the real field problem of the subsidence at the Ekofisk oil field in the Norwegian sector of the North Sea. The impact of various parameters of the model are verified by conducting sensitivity analyses. The results illustrate a significantly different behaviour for the case of a reservoir where the impact of coupling is also considered.

This thesis reports the results of an experimental investigation of vortex induced acoustic resonances in a rectangular duct containing two plates located in tandem. The effects of varying the plate spacing and the leading edge shape were investigated. Tests were conducted in both an open channel and in a rectangular wind tunnel. Measurements were made of acoustic amplitude, frequency and phase relationship between the acoustic field and cortex shedding. Short tests were also conducted with an absorber unit mounted in the wind tunnel wall. Results of tandem plate configuration showed in most cases the presence of two discrete resonances during which the phase of shedding of the first resonance is similar to that of the upstream plate alone while during the second resonance, there was a much smaller variation in phase. In between the two resonances, there was a sudden jump in phase and amplitude as the flow velocity was further increased due to the re-excitation of the resonance. The effect of varying the plate spacing has a marked effect on both the velocity range at which the resonances were excited and the natural Strouhal number. At some plate spacings, these two resonances were excited alternately while at other spacings, there was a wide break between them. The application of tandem plates as a general means to suppress resonance was unsuccessful. It was also found that resonance can be totally suppressed by using an absorber unit.

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An effective methodology for modelling particulate systems is presented within an explicit finite/discrete element framework. Issues related to contact resolution of the contact constitutive laws and kinematics relationship of particle of various geometry complexities (circular disk, ellipse particle, sphere, clumped or bonded disk and sphere particle) are presented and investigated. Particular emphasis is given to the specification of contact parameters of particle such as normal and tangential damping, cohesion and adhesion force, rotational damping and rolling resistance. Preliminary numerical test for simple particulate problem are carried out to support the validity of the contact algorithms implemented. The develop discrete contact algorithms are implemented to the numerical tool in order to simulate the particulate systems problem in industrial applications. Since there is a lack of theoretical and experimental solutions for some of the challenging problems of particulate system in industrial applications, the numerical contact scheme provides an alternative solution. The numerical simulation based on the developed contact algorithms is demonstrated on three main different industrial applications. The bucket filling process in mining operation, silo filling, hopper discharging, tumbling mills and screw feeder discharging in mineral processing and vibrating beds in chemical engineering. The particulate system for these industrial applications shows a good agreement in comparison with the qualitative and some quantitative results from the experiment.