The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Markus Bussmann - One of the best experts on this subject based on the ideXlab platform.
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oil particle separation in a Falling Sphere configuration effect of viscosity ratio interfacial tension
International Journal of Multiphase Flow, 2018Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:Abstract The separation of oil from a single oil-coated spherical particle Falling through an aqueous solution is evaluated as a function of viscosity ratio and interfacial tension. A solvent was used to modify the viscosity of the oil and a surfactant was used to modify the interfacial tension. The separation process is characterized with respect to a capillary number (ratio of viscous shear stress to interfacial tension) and the viscosity ratio (between the oil phase and the aqueous solution). The separation of oil from the Falling Sphere can be described as a two-stage process. The first stage is the deformation of the oil film coating the Sphere, leading to the formation of a thread or “tail” downstream of the particle. The second stage involves the breakup of that tail as the Sphere falls. The initial film deformation and tail formation is best described by a capillary number based on the shear rate at the oil-water interface; and the tail breakup by the rate of elongation experienced by the tail. More oil is removed when thicker tails are formed, which are obtained at high viscosity ratios. However, high viscosity ratios require longer shearing time for the tail to form. Our results indicate that maximum separation takes place when the viscosity ratio is between 0.1 and 1, with capillary numbers close to 1.
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Oil-particle separation in a Falling Sphere configuration: Effect of viscosity ratio & interfacial tension
International Journal of Multiphase Flow, 2017Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:Abstract The separation of oil from a single oil-coated spherical particle Falling through an aqueous solution is evaluated as a function of viscosity ratio and interfacial tension. A solvent was used to modify the viscosity of the oil and a surfactant was used to modify the interfacial tension. The separation process is characterized with respect to a capillary number (ratio of viscous shear stress to interfacial tension) and the viscosity ratio (between the oil phase and the aqueous solution). The separation of oil from the Falling Sphere can be described as a two-stage process. The first stage is the deformation of the oil film coating the Sphere, leading to the formation of a thread or “tail” downstream of the particle. The second stage involves the breakup of that tail as the Sphere falls. The initial film deformation and tail formation is best described by a capillary number based on the shear rate at the oil-water interface; and the tail breakup by the rate of elongation experienced by the tail. More oil is removed when thicker tails are formed, which are obtained at high viscosity ratios. However, high viscosity ratios require longer shearing time for the tail to form. Our results indicate that maximum separation takes place when the viscosity ratio is between 0.1 and 1, with capillary numbers close to 1.
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Oil–Particle Separation in a Falling Sphere Configuration: Effect of Oil Film Thickness
Energy & Fuels, 2016Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:High-speed videos of oil-coated solid Spheres Falling through an aqueous solution were analyzed to determine the amount of oil separated and the velocity of the coated Sphere during free fall. The oil-coated Sphere configuration is relevant to understanding the recovery of oil from oil sands; hence, bitumen was used as the oil phase. A new form of a capillary number based on a low-Reynolds number solution is introduced to characterize the separation process. The proposed particle-based capillary number takes into account the effect of the oil film thickness and the viscosity ratio. In this study, the separation of oil from an oil-coated Sphere is examined as a function of the oil film thickness, while keeping the viscosity ratio constant at 0.08. From the experimental results, it was observed that there is a critical oil film thickness beyond which oil separation from a particle is observed. Higher oil removal efficiencies are obtained at higher oil film thicknesses. The velocity of an oil-coated Sphere i...
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oil particle separation in a Falling Sphere configuration effect of oil film thickness
Energy & Fuels, 2016Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:High-speed videos of oil-coated solid Spheres Falling through an aqueous solution were analyzed to determine the amount of oil separated and the velocity of the coated Sphere during free fall. The oil-coated Sphere configuration is relevant to understanding the recovery of oil from oil sands; hence, bitumen was used as the oil phase. A new form of a capillary number based on a low-Reynolds number solution is introduced to characterize the separation process. The proposed particle-based capillary number takes into account the effect of the oil film thickness and the viscosity ratio. In this study, the separation of oil from an oil-coated Sphere is examined as a function of the oil film thickness, while keeping the viscosity ratio constant at 0.08. From the experimental results, it was observed that there is a critical oil film thickness beyond which oil separation from a particle is observed. Higher oil removal efficiencies are obtained at higher oil film thicknesses. The velocity of an oil-coated Sphere i...
Sasan Mehrabian - One of the best experts on this subject based on the ideXlab platform.
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oil particle separation in a Falling Sphere configuration effect of viscosity ratio interfacial tension
International Journal of Multiphase Flow, 2018Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:Abstract The separation of oil from a single oil-coated spherical particle Falling through an aqueous solution is evaluated as a function of viscosity ratio and interfacial tension. A solvent was used to modify the viscosity of the oil and a surfactant was used to modify the interfacial tension. The separation process is characterized with respect to a capillary number (ratio of viscous shear stress to interfacial tension) and the viscosity ratio (between the oil phase and the aqueous solution). The separation of oil from the Falling Sphere can be described as a two-stage process. The first stage is the deformation of the oil film coating the Sphere, leading to the formation of a thread or “tail” downstream of the particle. The second stage involves the breakup of that tail as the Sphere falls. The initial film deformation and tail formation is best described by a capillary number based on the shear rate at the oil-water interface; and the tail breakup by the rate of elongation experienced by the tail. More oil is removed when thicker tails are formed, which are obtained at high viscosity ratios. However, high viscosity ratios require longer shearing time for the tail to form. Our results indicate that maximum separation takes place when the viscosity ratio is between 0.1 and 1, with capillary numbers close to 1.
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Oil-particle separation in a Falling Sphere configuration: Effect of viscosity ratio & interfacial tension
International Journal of Multiphase Flow, 2017Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:Abstract The separation of oil from a single oil-coated spherical particle Falling through an aqueous solution is evaluated as a function of viscosity ratio and interfacial tension. A solvent was used to modify the viscosity of the oil and a surfactant was used to modify the interfacial tension. The separation process is characterized with respect to a capillary number (ratio of viscous shear stress to interfacial tension) and the viscosity ratio (between the oil phase and the aqueous solution). The separation of oil from the Falling Sphere can be described as a two-stage process. The first stage is the deformation of the oil film coating the Sphere, leading to the formation of a thread or “tail” downstream of the particle. The second stage involves the breakup of that tail as the Sphere falls. The initial film deformation and tail formation is best described by a capillary number based on the shear rate at the oil-water interface; and the tail breakup by the rate of elongation experienced by the tail. More oil is removed when thicker tails are formed, which are obtained at high viscosity ratios. However, high viscosity ratios require longer shearing time for the tail to form. Our results indicate that maximum separation takes place when the viscosity ratio is between 0.1 and 1, with capillary numbers close to 1.
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Oil–Particle Separation in a Falling Sphere Configuration: Effect of Oil Film Thickness
Energy & Fuels, 2016Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:High-speed videos of oil-coated solid Spheres Falling through an aqueous solution were analyzed to determine the amount of oil separated and the velocity of the coated Sphere during free fall. The oil-coated Sphere configuration is relevant to understanding the recovery of oil from oil sands; hence, bitumen was used as the oil phase. A new form of a capillary number based on a low-Reynolds number solution is introduced to characterize the separation process. The proposed particle-based capillary number takes into account the effect of the oil film thickness and the viscosity ratio. In this study, the separation of oil from an oil-coated Sphere is examined as a function of the oil film thickness, while keeping the viscosity ratio constant at 0.08. From the experimental results, it was observed that there is a critical oil film thickness beyond which oil separation from a particle is observed. Higher oil removal efficiencies are obtained at higher oil film thicknesses. The velocity of an oil-coated Sphere i...
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oil particle separation in a Falling Sphere configuration effect of oil film thickness
Energy & Fuels, 2016Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:High-speed videos of oil-coated solid Spheres Falling through an aqueous solution were analyzed to determine the amount of oil separated and the velocity of the coated Sphere during free fall. The oil-coated Sphere configuration is relevant to understanding the recovery of oil from oil sands; hence, bitumen was used as the oil phase. A new form of a capillary number based on a low-Reynolds number solution is introduced to characterize the separation process. The proposed particle-based capillary number takes into account the effect of the oil film thickness and the viscosity ratio. In this study, the separation of oil from an oil-coated Sphere is examined as a function of the oil film thickness, while keeping the viscosity ratio constant at 0.08. From the experimental results, it was observed that there is a critical oil film thickness beyond which oil separation from a particle is observed. Higher oil removal efficiencies are obtained at higher oil film thicknesses. The velocity of an oil-coated Sphere i...
R P Chhabra - One of the best experts on this subject based on the ideXlab platform.
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wall effects on a Sphere Falling in power law fluids in cylindrical tubes
2009Co-Authors: Daoyun Song, Rakesh K Gupta, R P ChhabraAbstract:The effect of finite boundaries on the drag experienced by a Sphere settling in quiescent power law fluids in cylindrical vessels has been investigated numerically. In particular, the momentum equations have been solved numerically over the following ranges of conditions: Sphere Reynolds number, 1-100; power law index, 0.2-1; and Sphere-to-tube diameter ratio, 0-0.5. Due to the backflow of the fluid caused by a Falling Sphere and the corresponding changes in the velocity field close to the Sphere, the presence of finite boundaries leads to an increase in the drag force acting on a Falling Sphere thereby slowing its descent. The effect, however, is more significant at low Reynolds numbers than at high Reynolds numbers. Similarly, the additional drag due to the walls increases with the increasing degree of confinement, i.e., the Sphere-to-tube diameter ratio. Overall, all else being equal, the wall effect is less severe in power law fluids than in Newtonian fluids. Furthermore, the confining walls also influence the onset of flow separation and subsequently the size of the recirculation region. The present numerical predictions are consistent with the experimental results available in the literature.
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wall effects on a Sphere Falling in quiescent power law fluids in cylindrical tubes
Industrial & Engineering Chemistry Research, 2009Co-Authors: Daoyun Song, Rakesh K Gupta, R P ChhabraAbstract:The effect of finite boundaries on the drag experienced by a Sphere settling in quiescent power law fluids in cylindrical vessels has been investigated numerically. In particular, the momentum equations have been solved numerically over the following ranges of conditions: Sphere Reynolds number, 1−100; power law index, 0.2−1; and Sphere-to-tube diameter ratio, 0−0.5. Due to the backflow of the fluid caused by a Falling Sphere and the corresponding changes in the velocity field close to the Sphere, the presence of finite boundaries leads to an increase in the drag force acting on a Falling Sphere thereby slowing its descent. The effect, however, is more significant at low Reynolds numbers than at high Reynolds numbers. Similarly, the additional drag due to the walls increases with the increasing degree of confinement, i.e., the Sphere-to-tube diameter ratio. Overall, all else being equal, the wall effect is less severe in power law fluids than in Newtonian fluids. Furthermore, the confining walls also infl...
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accelerating motion of a vertically Falling Sphere in incompressible newtonian media an analytical solution
Powder Technology, 1998Co-Authors: J M Ferreira, R P ChhabraAbstract:Abstract The transient motion of a Sphere Falling through a Newtonian fluid has been investigated using a drag of the form given by Abraham/ Wadell, the average accuracy of which was found to be 7.6% for a Sphere with Reynolds number Re in the range 0
Edgar Acosta - One of the best experts on this subject based on the ideXlab platform.
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oil particle separation in a Falling Sphere configuration effect of viscosity ratio interfacial tension
International Journal of Multiphase Flow, 2018Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:Abstract The separation of oil from a single oil-coated spherical particle Falling through an aqueous solution is evaluated as a function of viscosity ratio and interfacial tension. A solvent was used to modify the viscosity of the oil and a surfactant was used to modify the interfacial tension. The separation process is characterized with respect to a capillary number (ratio of viscous shear stress to interfacial tension) and the viscosity ratio (between the oil phase and the aqueous solution). The separation of oil from the Falling Sphere can be described as a two-stage process. The first stage is the deformation of the oil film coating the Sphere, leading to the formation of a thread or “tail” downstream of the particle. The second stage involves the breakup of that tail as the Sphere falls. The initial film deformation and tail formation is best described by a capillary number based on the shear rate at the oil-water interface; and the tail breakup by the rate of elongation experienced by the tail. More oil is removed when thicker tails are formed, which are obtained at high viscosity ratios. However, high viscosity ratios require longer shearing time for the tail to form. Our results indicate that maximum separation takes place when the viscosity ratio is between 0.1 and 1, with capillary numbers close to 1.
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Oil-particle separation in a Falling Sphere configuration: Effect of viscosity ratio & interfacial tension
International Journal of Multiphase Flow, 2017Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:Abstract The separation of oil from a single oil-coated spherical particle Falling through an aqueous solution is evaluated as a function of viscosity ratio and interfacial tension. A solvent was used to modify the viscosity of the oil and a surfactant was used to modify the interfacial tension. The separation process is characterized with respect to a capillary number (ratio of viscous shear stress to interfacial tension) and the viscosity ratio (between the oil phase and the aqueous solution). The separation of oil from the Falling Sphere can be described as a two-stage process. The first stage is the deformation of the oil film coating the Sphere, leading to the formation of a thread or “tail” downstream of the particle. The second stage involves the breakup of that tail as the Sphere falls. The initial film deformation and tail formation is best described by a capillary number based on the shear rate at the oil-water interface; and the tail breakup by the rate of elongation experienced by the tail. More oil is removed when thicker tails are formed, which are obtained at high viscosity ratios. However, high viscosity ratios require longer shearing time for the tail to form. Our results indicate that maximum separation takes place when the viscosity ratio is between 0.1 and 1, with capillary numbers close to 1.
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Oil–Particle Separation in a Falling Sphere Configuration: Effect of Oil Film Thickness
Energy & Fuels, 2016Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:High-speed videos of oil-coated solid Spheres Falling through an aqueous solution were analyzed to determine the amount of oil separated and the velocity of the coated Sphere during free fall. The oil-coated Sphere configuration is relevant to understanding the recovery of oil from oil sands; hence, bitumen was used as the oil phase. A new form of a capillary number based on a low-Reynolds number solution is introduced to characterize the separation process. The proposed particle-based capillary number takes into account the effect of the oil film thickness and the viscosity ratio. In this study, the separation of oil from an oil-coated Sphere is examined as a function of the oil film thickness, while keeping the viscosity ratio constant at 0.08. From the experimental results, it was observed that there is a critical oil film thickness beyond which oil separation from a particle is observed. Higher oil removal efficiencies are obtained at higher oil film thicknesses. The velocity of an oil-coated Sphere i...
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oil particle separation in a Falling Sphere configuration effect of oil film thickness
Energy & Fuels, 2016Co-Authors: Sasan Mehrabian, Edgar Acosta, Markus BussmannAbstract:High-speed videos of oil-coated solid Spheres Falling through an aqueous solution were analyzed to determine the amount of oil separated and the velocity of the coated Sphere during free fall. The oil-coated Sphere configuration is relevant to understanding the recovery of oil from oil sands; hence, bitumen was used as the oil phase. A new form of a capillary number based on a low-Reynolds number solution is introduced to characterize the separation process. The proposed particle-based capillary number takes into account the effect of the oil film thickness and the viscosity ratio. In this study, the separation of oil from an oil-coated Sphere is examined as a function of the oil film thickness, while keeping the viscosity ratio constant at 0.08. From the experimental results, it was observed that there is a critical oil film thickness beyond which oil separation from a particle is observed. Higher oil removal efficiencies are obtained at higher oil film thicknesses. The velocity of an oil-coated Sphere i...
John R De Bruyn - One of the best experts on this subject based on the ideXlab platform.
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drag force on a Sphere in steady motion through a yield stress fluid
Journal of Rheology, 2007Co-Authors: Herve Tabuteau, P Coussot, John R De BruynAbstract:We have studied the motion of Spheres Falling through yield-stress Carbopol gels. We measured the velocity of the Falling Sphere as a function of time and Sphere density. Reproducible results were obtained when the experimental fluids were carefully prepared and homogenized. Three regimes of motion were observed. Spheres of high enough density reached a constant terminal velocity, as in Newtonian fluids. Below a critical density, the Sphere came to a complete stop, while in an intermediate regime, the Sphere continued to move but with a velocity which steadily decreased with time. We have also carefully characterized the rheological behavior of the fluids. The flow regimes observed for the Falling Sphere are analogous to those observed in creep tests for different applied stress levels. The yielding criterion and the drag force on the Sphere obtained from our data are in excellent agreement with the longstanding but previously unconfirmed theoretical predictions of Beris et al. [J. Fluid Mech. 158, 219–24...