Begell House Inc.
Multiphase Science and Technology
MST
0276-1459
26
3
2014
A REVIEW OF LIQUID-LIQUID FLOW PATTERNS IN HORIZONTAL AND SLIGHTLY INCLINED PIPES
171-198
10.1615/MultScienTechn.v26.i3.10
Roberto
Ibarra
Department of Chemical Engineering, Imperial College London
Christos N.
Markides
Clean Energy Processes (CEP) Laboratory, Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
Omar K.
Matar
Department of Chemical Engineering, Imperial College London, Prince Consort Road, London SW7 2AZf, UK; The Alan Turing Institute, British Library, 96 Euston Road, London, NW1 2DB, UK
horizontal liquid-liquid flow
inclined liquid-liquid flow
flow pattern map
flow pattern classification
This paper presents a review of the co-current flow of two immiscible liquids in horizontal and slightly inclined pipes. Liquid-liquid flows are present in a wide variety of industrial processes, such as chemicals, pharmaceuticals, and food processing. However, this phenomenon is mainly studied in the oil industry, especially in the analysis of oil-water mixtures encountered in long transportation pipelines from the wellhead to the processing facility. The hydrodynamic behavior of liquid-liquid flows is more complex than that of gas-liquid flows because of density ratio, viscosity ratio, interfacial forces, and pipe wettability. This means that a significant number of different flow patterns can be obtained from different fluid properties and pipe characteristics. Furthermore, the flow pattern classification of liquid-liquid flows is arbitrary and several researchers use their own classification, complicating comparison and analysis of flow pattern maps. In this paper, a unified flow pattern classification for liquid-liquid flow is proposed. This classification enables the direct comparison of flow pattern maps for further analysis.
MODELING SOLID-LIQUID HOMOGENEOUS TURBULENT FLOW OF NEUTRALLY BUOYANT PARTICLES USING THE MIXTURE MODEL: A STUDY OF LENGTH SCALES AND CLOSURE COEFFICIENTS
199-227
10.1615/MultScienTechn.v26.i3.20
Rui
Silva
Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
F. A. P.
Garcia
Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
P.
Faia
Electrical and Computer Engineering, Faculty of Sciences and Technology, University of Coimbra, Portugal
M. G.
Rasteiro
Department of Chemical Engineering, University of Coimbra, 3030-290 Coimbra
mixture model
homogeneous solid-liquid suspensions
turbulence scales
closure coefficients
buoyant particles
Numerical studies employing the mixture model were used to evaluate, through sensitivity analysis, the influence of closure coefficients and turbulence scales on a fully developed homogeneous solid-liquid suspension flow. A standard k-ε turbulence model was employed with a 20% increase for each closure coefficient; its effect was evaluated and compared with results in the literature. For turbulence length scales, several methods described in the literature served as references. The numerical results of the mixture model simulations, for a fully developed homogenous flow of solid-liquid suspensions in a circular pipe section, were compared with those in the literature. Overall, the obtained results and the literature results matched, validating the model for use with fully developed flow of neutrally buoyant particle suspensions.
GAS-PHASE PROBABILITY DISTRIBUTION IN LIQUID CROSS-FLOW
229-260
10.1615/MultScienTechn.v26.i3.30
Miguel A.
Balzan
Mechanical Engineering Department, University of Alberta, 4-9 Mechanical Engineering Building, Edmonton, AB, T6G 2G8, Canada
Brian A.
Fleck
Mechanical Engineering Department, University of Alberta, 4-9 Mechanical Engineering Building, Edmonton, AB, T6G 2G8, Canada
gas injection
centerline trajectory
gas-liquid flow
borderline trajectory
The interaction of an air jet in liquid water cross-flow in the vicinity of a gas injector was experimentally investigated using high-speed shadowgraphy. A turbulent, fully developed water flow, with superficial water velocity values of 1.9-4.3 m/s, was circulated through a 12.7-mm square channel of 118 cm in length. Three gas nozzles, with diameters of 0.27 mm, 0.52 mm, and 1.59 mm, were used to inject the air perpendicularly into the water flow. The gas mass flow rates ranged from 10-60 × 10-3 g/s. An image-processing algorithm was used to estimate the incipient centerline and borderline trajectories of the gas phase during its initial interaction with the liquid. Experimental results were compared with existing correlations developed for standard jets in a cross-flow and showed limited agreement. The lack of correlation specifically for gas jets in a cross-flowing liquid is substantial. For this reason, original empirical expressions based on dimensionless parameters were introduced. The assessment of the correlations indicated a dependable prediction of the initial centerline and borderline trajectories of the gas jet in liquid.