Begell House Inc.
Multiphase Science and Technology
MST
0276-1459
24
4
2012
BUBBLE MEASUREMENTS IN LIQUID-METAL TWO-PHASE FLOW BY USING A FOUR-SENSOR PROBE
279-297
10.1615/MultScienTechn.v24.i4.10
Yasushi
Saito
Institute for Integrated Radiation and Nuclear Science, Kyoto University, 2,
Asashiro-Nishi, Kumatori-cho, Osaka 590-0494, Japan
Kaichiro
Mishima
Institute of Nuclear Safety System, Inc., 64 Sata, Mihama, Mikata, Fukui 919-1205, Japan
liquid metal
interfacial area concentration
two-phase flow
four-sensor probe
Liquid metal two-phase flow was measured by using a four-sensor electrical conductivity probe. The bubble velocity and diameter were calculated from the interfacial normal velocity vectors by assuming the bubble shape. The signal processing algorithm was verified numerically and experimentally with airwater two-phase flow. A leadbismuth eutectic test loop was used to measure the flow characteristics of the liquid-metal two-phase flow in a vertical round pipe. From the experimental results, the large bubble contact angle causes severe measurement error in estimating the bubble velocity due to the interface curvature. By neglecting the bubble signal with a large contact angle, reasonable bubble velocity profiles were obtained and compared with existing correlations. From these measurements, the measurement error and basic characteristics of gasliquid-metal two-phase flow were clarified.
NUMERICAL MODELING OF GAS-SOLID FLOW IN A HORIZONTAL PIPE
299-322
10.1615/MultScienTechn.v24.i4.20
Brundaban
Patro
National Institute of Technology Warangal, Telangana 506004, India
S.
Murugan
Department of Mechanical Engineering, National Institute of Technology, Rourkela-769008, Odisha, India
Pandaba
Patro
Veer Surendra Sai University of Technology, Odisha, India
gas-solid flow
horizontal pipe
computational fluid dynamics
Euler-Euler approach
four-way coupling
This paper presents the numerical prediction of the pressure drop in a horizontal pipe with an internal diameter of 30 mm and length of 3000 mm. The validation is done using experimental data available in the literature, and good agreement is found. The effects of the particle diameter and particle density on the pressure drop in the pipe are analyzed. For the study, a three-dimensional horizontal pipe is used to numerically predict the static pressure drop in gas−solid flows by means of the computational fluid dynamics commercial software FLUENT 6.3. Different particle diameters ranging from 20 to 150 µm and particle densities ranging from 1000 to 2600 kg/m3 are used in the present simulations, along with the Euler−Euler approach, accounting for four-way coupling. The results indicate that the pressure drop rapidly increases with the particle diameter, reaches a peak value, and then begins to decrease. The results also show that the pressure drop increases with an increase in the particle density.
REVIEW STUDY ON AIRLIFT PUMPING SYSTEMS
323-362
10.1615/MultScienTechn.v24.i4.30
Pedram
Hanafizadeh
Center of Excellence in Design and Optimization of Energy Systems, School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran
B.
Ghorbani
Center of Excellence in Design and Optimization of Energy Systems, School of Mechanical Engineering, College of Engineering, University of Tehran, P.O. Box: 11155-4563, Tehran, Iran
airlift system
multiphase flow
gas-liquid flow
submergence ratio
flow regimes
flow patterns
Airlift systems are widely used in various fields such as in the petrochemical and oil industries. Because the main part of the flow through the pipe of these systems is formed by gasliquid two-phase flow, analysis of such systems are accompanied with problems of two-phase flow modeling. Several effective variables are involved in airlift systems; therefore, a comprehensive method is needed when considering these parameters. This paper reviews the state of the art in the field of airlift systems. All of the related articles have been divided into two categories; namely, two-phase and three-phase systems based on the operation of the airlift systems in the fluids. Moreover, the paper describes the airlift pump operation as a kind of pumping system and evaluates developments in the modeling of these systems. In particular, the paper also concentrates on airlift history and background, structure, types, and applications.