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Fluid properties determine flow line blockage potential
112
ANNUAL LITERATURE SURVEY 1996
ment. This paper is on the employment of chaos theory to describe this structure. The measuring technique of electrical capacitance tomography is used to determine the local porosity of a gas-solids fluidized bed and to monitor its fluctuation with time. These raw data are translated into invariants characteristic of the structure mentioned, such as the Kolmogorov entropy. Initial measurements have shown a strong variation in these chaotic invariants with bed position and operational parameters. First results are compared with earlier data from pressure measurements. (Authors)
Development of an ultrasonic tomography system for application in pneumatic conveying Brown G.J., Reilly D. & Mills D., Measurement Science & Technology, 1996, 7/3 (396-405). In English. This paper details the development of a tomographic technique for imaging gas-solid flow distributions in pneumatic conveying pipelines. The technique utilizes ultrasonic transmission-mode measurements constrained to the megahertz region. Image reconstruction is performed by an efficient backprojection method implemented with standard graphics algorithms. Simulated reconstructions of dense and dilute distributions are presented. These results demonstrate the capabilities and limitations of the technique. Aspects of transducers array design are also addressed. An optimal arrangement for imaging dense phase flow distributions is derived and the characteristics of air-loaded and water-loaded, matched and unmatched peizoceramic transducers are evaluated. The validity of the technique is demonstrated using a low-frequency (72 kHz) system constructed with prototype fan-shaped-beam electrostatic transducers. (from Authors) Simulator predicts transient flow for Malaysian subsea pipeline Inayat-Hussain A.A., Ayob M.S. & Zain A.B.M., Oil & Gas Journal, 1996, 94/16 (62-64,67). In English. ABASs is dedicated software developed for two-phase flow simulation of slow gas condensate transient flow during pigging operations in the Duyong pipeline network offshore Malaysia. It predicts steady state pressure drop against flow rate, condensate volume, and pigging dynamics. Predictions have been verified against field data. This article describes software development, verification and application. Field data and results of simulation studies are included. (J.M.McLaughlin) Fluid properties determine flow line blockage potential Hunt A., Oil & Gas Journal, 1996, 94/29 (62-66). In English. Thermal and chemical methods are described for overcoming fluid behaviour problems caused by hydrate and other fluid constituents in subsea multiphase flow. Types of problems and their causes are discussed. The differences between nucleation, growth and deposition in the pipelines are considered. Process simulation packages for predicting hydrate formation conditions within the pipeline are described. The use of thermodynamic and kinetic inhibitors for preventing hydrate formation is discussed. (P.M.Taylor) Multiphase-flow choke correlation limits analyzed Lannom D.A. & Hatzignatiou D.G., Oil & Gas Journal, 1996, 94/15 (37-41). In English. Correlations for determining the flow rate of multiphase fluids through restrictions are examined. The seven correlations are evaluated using production data from 181 well tests. Parameters influencing the performance and selection of each correlation are discussed. Although no one correlation performed best in all ranges of flow parameters, the Gilbert, Ros, and Poetmann and Beck correlations tended to predict flow rates more accurately over the widest range of flow conditions. (P.M.Taylor) Fluid properties determine flow line blockage potential Hunt A., Oil & Gas Journal, 1996, 94/29 (62-66). In English. Thermal and chemical methods are described for overcoming fluid behaviour problems caused by hydrate and other fluid constituents in subsea multiphase flow. Types of problems and their causes are discussed. The differences between nucleation, growth and deposition in the pipelines are considered. Process simulation packages for predicting hydrate formation conditions within the pipeline are described. The use of thermodynamic and kinetic inhibitors for preventing hydrate formation is discussed. (P.M.Taylor) Shock waves in a liquid containing small gas bubbles Kameda M. & Matsumoto Y., Physics of Fluids, 1996, 8/2 (322-335). In English. Numerical and experimental studies of the transient shock wave phenomena in a liquid containing non-condensable gas bubbles are presented. In the numerical analysis, individual bubbles are tracked to estimate the effect of volume oscillations on the wave phenomena. Thermal processes inside each bubble, which have significant influence on the volume oscillation, are calculated directly using full equations for mass, momentum and energy conservation, and those results are combined with the averaged conservation equations of the bubbly mixture to simulate the propagation of the shock wave. A silicon oil/nitrogen bubble mixture, in which the initial bubble radius is about 0.6 mm and the gas volume fraction is 0.15%-0.4%, is used in the shock tube experiments. The numerical predictions where such a distribution is taken into account agree well with those experimental data. Wave phenomena in bubbly mixture, which has close connection with the performance of chemical reactors, safety of nuclear power plants, performance of oceanic devices. Heat transfer between the bubbles and the surrounding liquid, rather than relative motion, is the main factor affecting the relaxation process. The heat transfer is governed by the thermal behavior of the bubble interior. (after Authors) Observations of a cavitation bubble interacting with a solid boundary as seen from below Jin Y.H., Shaw S.J. & Emmony D.C., Physics of Fluids, 1996, 8/7 (1699-1701). In English. This paper looks at cavitation which is the process by which vapour cavities or bubbles, when they come close to a solid boundary, cause damage to that surface. We present a schlieren photographic sequence of a laser generated cavity in water interacting with a solid boundary as seen from the boundary's perspective looking through the bubble. (after Authors)
ANNUAL LITERATURE SURVEY 1996
ment. This paper is on the employment of chaos theory to describe this structure. The measuring technique of electrical capacitance tomography is used to determine the local porosity of a gas-solids fluidized bed and to monitor its fluctuation with time. These raw data are translated into invariants characteristic of the structure mentioned, such as the Kolmogorov entropy. Initial measurements have shown a strong variation in these chaotic invariants with bed position and operational parameters. First results are compared with earlier data from pressure measurements. (Authors)
Development of an ultrasonic tomography system for application in pneumatic conveying Brown G.J., Reilly D. & Mills D., Measurement Science & Technology, 1996, 7/3 (396-405). In English. This paper details the development of a tomographic technique for imaging gas-solid flow distributions in pneumatic conveying pipelines. The technique utilizes ultrasonic transmission-mode measurements constrained to the megahertz region. Image reconstruction is performed by an efficient backprojection method implemented with standard graphics algorithms. Simulated reconstructions of dense and dilute distributions are presented. These results demonstrate the capabilities and limitations of the technique. Aspects of transducers array design are also addressed. An optimal arrangement for imaging dense phase flow distributions is derived and the characteristics of air-loaded and water-loaded, matched and unmatched peizoceramic transducers are evaluated. The validity of the technique is demonstrated using a low-frequency (72 kHz) system constructed with prototype fan-shaped-beam electrostatic transducers. (from Authors) Simulator predicts transient flow for Malaysian subsea pipeline Inayat-Hussain A.A., Ayob M.S. & Zain A.B.M., Oil & Gas Journal, 1996, 94/16 (62-64,67). In English. ABASs is dedicated software developed for two-phase flow simulation of slow gas condensate transient flow during pigging operations in the Duyong pipeline network offshore Malaysia. It predicts steady state pressure drop against flow rate, condensate volume, and pigging dynamics. Predictions have been verified against field data. This article describes software development, verification and application. Field data and results of simulation studies are included. (J.M.McLaughlin) Fluid properties determine flow line blockage potential Hunt A., Oil & Gas Journal, 1996, 94/29 (62-66). In English. Thermal and chemical methods are described for overcoming fluid behaviour problems caused by hydrate and other fluid constituents in subsea multiphase flow. Types of problems and their causes are discussed. The differences between nucleation, growth and deposition in the pipelines are considered. Process simulation packages for predicting hydrate formation conditions within the pipeline are described. The use of thermodynamic and kinetic inhibitors for preventing hydrate formation is discussed. (P.M.Taylor) Multiphase-flow choke correlation limits analyzed Lannom D.A. & Hatzignatiou D.G., Oil & Gas Journal, 1996, 94/15 (37-41). In English. Correlations for determining the flow rate of multiphase fluids through restrictions are examined. The seven correlations are evaluated using production data from 181 well tests. Parameters influencing the performance and selection of each correlation are discussed. Although no one correlation performed best in all ranges of flow parameters, the Gilbert, Ros, and Poetmann and Beck correlations tended to predict flow rates more accurately over the widest range of flow conditions. (P.M.Taylor) Fluid properties determine flow line blockage potential Hunt A., Oil & Gas Journal, 1996, 94/29 (62-66). In English. Thermal and chemical methods are described for overcoming fluid behaviour problems caused by hydrate and other fluid constituents in subsea multiphase flow. Types of problems and their causes are discussed. The differences between nucleation, growth and deposition in the pipelines are considered. Process simulation packages for predicting hydrate formation conditions within the pipeline are described. The use of thermodynamic and kinetic inhibitors for preventing hydrate formation is discussed. (P.M.Taylor) Shock waves in a liquid containing small gas bubbles Kameda M. & Matsumoto Y., Physics of Fluids, 1996, 8/2 (322-335). In English. Numerical and experimental studies of the transient shock wave phenomena in a liquid containing non-condensable gas bubbles are presented. In the numerical analysis, individual bubbles are tracked to estimate the effect of volume oscillations on the wave phenomena. Thermal processes inside each bubble, which have significant influence on the volume oscillation, are calculated directly using full equations for mass, momentum and energy conservation, and those results are combined with the averaged conservation equations of the bubbly mixture to simulate the propagation of the shock wave. A silicon oil/nitrogen bubble mixture, in which the initial bubble radius is about 0.6 mm and the gas volume fraction is 0.15%-0.4%, is used in the shock tube experiments. The numerical predictions where such a distribution is taken into account agree well with those experimental data. Wave phenomena in bubbly mixture, which has close connection with the performance of chemical reactors, safety of nuclear power plants, performance of oceanic devices. Heat transfer between the bubbles and the surrounding liquid, rather than relative motion, is the main factor affecting the relaxation process. The heat transfer is governed by the thermal behavior of the bubble interior. (after Authors) Observations of a cavitation bubble interacting with a solid boundary as seen from below Jin Y.H., Shaw S.J. & Emmony D.C., Physics of Fluids, 1996, 8/7 (1699-1701). In English. This paper looks at cavitation which is the process by which vapour cavities or bubbles, when they come close to a solid boundary, cause damage to that surface. We present a schlieren photographic sequence of a laser generated cavity in water interacting with a solid boundary as seen from the boundary's perspective looking through the bubble. (after Authors)