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    Comparative Assessment of Non-newtonian Single-Phase and Two-Phase Approaches for Numerical Studies of Centrifugal Pumps Handling Emulsion
    (Springer Nature, 2024) Achour, Lila; Specklin, Mathieu; Asuaje, Miguel; Kouidri, Smaine; Belaidi, Idir
    Computational Fluid Dynamics is commonly employed to assess the effect of oil-water emulsions on pump performance, usually using two-phase models. However, these models often neglect the emulsion’s non-Newtonian behavior, despite its known experimental significance in enhancing pump performance. This study attempts to evaluate both single-phase non-Newtonian and two-phase approaches to model emulsion flow within centrifugal pumps. The non-Newtonian single-phase and several two-phase models are evaluated by comparing the predicted pump heads with experimental data of a multistage pump from the literature. The findings show that the non-Newtonian single-phase model generally provides better agreement with experimental measurements, particularly for emulsions with low dispersed phase fractions. Nevertheless, for emulsions with a high dispersed phase fraction (≈ 50%), the difference between the two approaches is insignificant. Thus, due to the lack of a universal multiphase model for emulsion simulation, the non-Newtonian single-phase model can serve as a viable alternative, overcoming the limitations of two-phase approaches in simulating complex multiphase fluid systems.
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    A review of emulsion flows, their characterization and their modeling in pumps
    (Institution of Chemical Engineers, 2024) Achour, Lila; Specklin, Mathieu; Asuaje, Miguel; Kouidri, Smaine; Belaidi, Idir
    In the engineering field, emulsions and liquid–liquid two-phase flows within centrifugal pumps are generally unwanted as emulsions will have negative effects on pump operation. Besides, emulsions are usually formed when the oil and water phases are brought together in a process called emulsification, which is enhanced by high shear rates. This topic has been extensively researched over the past decades, with sophisticated theories regarding the phenomena involved in emulsions formation and characterization in pumps. Besides, given the complexity of the physics governing emulsions, studies on their modeling within pumps, based on empirical correlations or computational fluid dynamics models, are insufficient and remain limited. This review aims to provide a complete overview of investigations on liquid–liquid flow in centrifugal pumps. Characteristics of these mixtures, such as stability, phase inversion, droplet size distribution and rheological behavior, are discussed. Current approaches and techniques for analyzing pump performance handling emulsion and two-phase liquid–liquid flow are reviewed thoroughly. The limitations of the existing models are studied, and potential future developments are proposed.
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    Rheological behavior and microstructural properties of crude oil and emulsions (water/oil-oil/water)
    (Taylor & Francis, 2024) Yacine, Celia; Safri, Abdelhamid; Djemiat, Djamal Eddine; Benmounah, Abdelbaki
    An experimental study on crude oil (from the Tin Fouye Tabankort oil field in southern Algeria) was carried out. This study allowed us to understand the rheological behavior of this crude oil with these different emulsions and how it reacts under the effects of temperature and the inversion of its phase from E/H to H/E. So we measured the rheological characteristics by tests flow and dynamic mode at different temperatures from 10 °C to 50 °C and at different water concentrations (20.40.50.60 and 70%) at a fixed temperature of 20 °C. The increase in temperature results in a 31.84% reduction in the initial viscosity of the crude oil. The addition of the volumic fractions of water results in an increase in viscosity at the point of inverse, which will decrease the apparent viscosity of these emulsions where the emulsions (W/O) come from (O/W). This crude oil and their emulsions exhibit a non-Newtonian behavior with shear thinning. The dynamic analysis depends on the temperature and the percentages of water added to the crude oil. At the end, a microscopic analysis was added to verify the relationship between the shape and diameter of the water droplets in each emulsion and the viscosity variation.
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    Numerical study of the performance loss of a centrifugal pump carrying emulsion
    (2021) Achour, Lila; Mathieu, Specklin; Belaidi, Idir; Kouidri, Smaine
    The performance and hydrodynamic behavior of cen- trifugal pumps when handling two-phase liquid-liquid flow and emulsion remain relatively unexplored, al- though they are of fundamental importance in optimiz- ing the operating conditions of these pumps. Hence, this study aims at investigating the performance degra- dation of a centrifugal pump under emulsion flow by combined means of analytical and computational fluid dynamic (CFD) models. The analytical approach is based on internal energy loss equations while the CFD approach models the emulsion as a continuous and ho- mogeneous single-phase fluid exhibiting shear thinning behavior. The results give a good insight into the per- formance degradation of such a system, especially at the best efficiency point (BEP).
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    A review on the rheology of heavy crude oil for pipeline transportation
    (ELSEVIER, 2020) Souas, Farid; Safri, Abdelhamid; Benmounah, Abdelbaki
    Given the combination of rising global energy demand and the decline in conventional crudes, heavy crudes are generally considered to be the future energy resource. In many regions of the world, heavy crude oil must be transported through pipelines from the point of production to storage facilities or refineries. The transportation of heavy crude oil by pipeline poses serious problems related to the high viscosity and flow difficulties, particularly in cold climates or offshore conditions. Indeed, the viscosity of crude oil is an important physical property that influences and controls crude oil flow in pipelines. Viscosity introduces resistance to movement by causing a shear or frictional force between the fluid particles and the boundary walls. This high viscosity means that the pumping power requirements for crude oil in a long-distance pipeline are very high in order to overcome the increasing shear and friction forces. Therefore, in order to facilitate the pumping of these viscous oils and reduce operating expenses and the negative impact of pressure drops in pipelines during flow and processing, their viscosity must be reduced. Various techniques are used to increase pumping efficiency and improve the flow of crude oil through the pipeline, which may present logistical, technical or economic disadvantages for a given application. The main ones are the addition of surfactants or polymers, dilution with lighter crudes, use of water as annular fluid, thermal remediation and emulsification with surfactant (O/W). This review highlights the methods currently used to enhance the fluidity of heavy crude oil in pipelines behind rheology improvement, in particular the addition of additives and the use of water and surfactants to create a stable emulsion of heavy crude oil in water have been considered.
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    Characterization of an effluent of an algerian oil mill
    (2012) Didouche, Yasmina-Fadila; Idouhar, M.
    This work concerns to characterize the effluent, a by-product of an Algerian oil mill, for its valorization. A microbiological study certified the healthiness of the effluent, followed by various means of analysis such as their observation under the microscope, water chemistry, thin layer chromatography, infrared and the ultra-violet spectrophotometry. The results of analyses suggest that the effluents is biodegradable (86.54 %) and present in form of an emulsion of type I i.e., oil-in-water mouthful of soap (15.5 g/L), bathing in conservatives. The results of a traditional analysis inherent in the soap corroborated these results. Moreover, a viscoplastic rheology was surrounded by the determination of various viscosities of the effluent, whose stability is ensured by the presence of contaminants, revealed by atomic absorption spectrophotometry