Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.506404
Title: One-dimensional modelling of mixing, dispersion and segregation of multiphase fluids flowing in pipelines
Author: Tomasello, Antonino
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2009
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Abstract:
The flow of immiscible liquids in pipelines has been studied in this work in order to formulatea one-dimensional model for the computer analysis of two-phase liquid-liquid flow in horizontalpipes. The model simplifies the number of flow patterns commonly encountered in liquid-liquidflow to stratified flow, fully dispersed flow and partial dispersion with the formation of one ortwo different emulsions. The model is based on the solution of continuity equations for dispersedand continuous phase; correlations available in the literature are used for the calculation of themaximum and mean dispersed phase drop diameter, the emulsion viscosity, the phase inversionpoint, the liquid-wall friction factors, liquid-liquid friction factors at interface and the slipvelocity between the phases. In absence of validated models for entrainment and depositionin liquid-liquid flow, two entrainment rate correlations and two deposition models originallydeveloped for gas-liquid flow have been adapted to liquid-liquid flow. The model was appliedto the flow of oil and water; the predicted flow regimes have been presented as a functionof the input water fraction and mixture velocity and compared with experimental results,showing an overall good agreement between calculation and experiments. Calculated valuesof oil-in-water and water-in-oil dispersed fractions were compared against experimental datafor different oil and water superficial velocities, input water fractions and mixture velocities. Pressure losses calculated in the full developed flow region of the pipe, a crucial quantity inindustrial applications, are reasonably close to measured values. Discrepancies and possibleimprovements of the model are also discussed. The model for two-phase flow was extended to three-phase liquid-liquid-gas flow withinthe framework of the two-fluid model. The two liquid phases were treated as a unique liquidphase with properly averaged properties. The model for three-phase flow thus developed wasimplemented in an existing research code for the simulation of three-phase slug flow with theformation of emulsions in the liquid phase and phase inversion phenomena. Comparisons withexperimental data are presented.
Supervisor: Issa, Raad ; Lawrence, Christopher Sponsor: Engineering and Physical Sciences Research Council (EPSRC) ; Department of Trade and Industry
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.506404  DOI: Not available
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