The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Hideki Tsuge - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Nozzle Shape on Bubble Formation from a Downward Nozzle
Chemical Engineering & Technology, 2006Co-Authors: Hideki Tsuge, Masae Mitsudani, Yusuke TezukaAbstract:A lot of research has been conducted on the gas injection methods; especially Bubble Formation from the upward orifice or nozzle, whereas few studies on Bubble Formation from the downward nozzle have been reported. In this study, the effects of both nozzle shape and diameter on the Bubble Formation mechanism from the vertically downward nozzle were investigated. The theoretical results obtained by applying the revised two-stage spherical Bubble Formation model for the downward nozzle was compared with the experimental results for small metal downward nozzles. The Bubble Formation mechanism and the Bubble size were influenced by the edge angle and diameter of the nozzle, respectively, and the gas flow rate.
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Bubble Formation at a nozzle submerged in viscous liquids having yield stress
Chemical Engineering Science, 2001Co-Authors: Koichi Terasaka, Hideki TsugeAbstract:Abstract The effects of operating conditions on Bubble volume formed from a nozzle submerged in some viscous media with yield stress were experimentally investigated. Pressure fluctuations in the gas chamber accompanied by Bubble Formation as well as Bubble growth curves were measured. By analysis of the time course of pressure change in the gas chamber, the dependency of the gas flow rate into the gas chamber and the chamber volume on the polytropic coefficient of gas in the gas chamber was discussed. To simulate the Bubble Formation at a single nozzle in a viscous medium having yield stress, the non-spherical Bubble Formation model was proposed. The calculated Bubble volumes agreed relatively well with the experimental ones.
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SO2 Bubble Formation at an Orifice Submerged in Water
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 1999Co-Authors: Koichi Terasaka, Yukiko Hieda, Hideki TsugeAbstract:To estimate mass transfer rate during Bubble Formation at an orifice, a theoretical model is proposed for soluble gas Bubble Formation in liquid by modifying the non-spherical Bubble Formation model. The absorption rate from pure SO2 gas Bubble to water is experimentally measured as well as Bubble shape and growth rate. Mass transfer from the gas-liquid interface during Bubble growth is described well by the penetration theory. Experimental Bubble shape, Bubble volume at its detachment from an orifice, growth rate and mass transfer rate are estimated well by the present model.
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Behavior of Bubble Formation at elevated pressure
Journal of Chemical Engineering of Japan, 1998Co-Authors: Koichi Terasaka, Hideki TsugeAbstract:In this study, Bubble Formation in high pressure systems is investigated. The volume and shape of Bubbles formed at an orifice submerged in liquid under high pressure are experimentally measured. To elucidate the Bubble Formation mechanism and to estimate the Bubble volume in high pressure systems, a non-spherical Bubble Formation model is used. When the volume and shape of the Bubble are calculated by the model under highly pressurized conditions, surface tension should be considered as a function of system pressure. The volume and shape of Bubble are estimated relatively well by the model, including the change in surface tension with the system pressure.
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Bubble Formation in flowing liquid under reduced gravity
Chemical Engineering Science, 1997Co-Authors: Hideki Tsuge, Koichi Terasaka, Yuko Tanaka, Hirokazu MatsueAbstract:Abstract A great deal of research has been done regarding Bubble Formation from submerged orifices in liquids under the force of gravity for the design of gas-liquid or gas-liquid-solid contacting equipment. On the other hand, little research has been done concerning Bubble Formation under reduced gravity conditions. For the basic design of the chemical process systems or life-support systems in space stations and on other planets, it is important to clarify the effects of various factors on the volume and shape of Bubbles formed at submerged orifices or nozzles under reduced gravity conditions. In order to disperse adequately Bubbles in liquids for mass transfer or chemical reaction processes at relatively low gas flow rates under reduced gravity, it is necessary to force Bubbles to become detached from nozzles by external forces. In this study, the liquid flow was used as the external force on Bubble Formation. The aim of this study is to clarify the behavior of Bubble Formation in flowing liquids under reduced gravity conditions. We experimentally investigated the effects of gas flow rate, liquid flow velocity, and liquid flow direction (cocurrent, countercurrent or cross-current flow) on Bubble Formation for a period of 1.2 s under reduced gravity conditions that were produced in the 10 m drop tower at the Hokkaido National Industrial Research Institute at Sapporo in Hokkaido. In order to describe theoretically the Bubble Formation in flowing liquids under reduced gravity conditions, a revised non-spherical Bubble Formation model was proposed and the calculated results of the Bubble volume were compared with the experimental ones.
Koichi Terasaka - One of the best experts on this subject based on the ideXlab platform.
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Bubble Formation at a nozzle submerged in viscous liquids having yield stress
Chemical Engineering Science, 2001Co-Authors: Koichi Terasaka, Hideki TsugeAbstract:Abstract The effects of operating conditions on Bubble volume formed from a nozzle submerged in some viscous media with yield stress were experimentally investigated. Pressure fluctuations in the gas chamber accompanied by Bubble Formation as well as Bubble growth curves were measured. By analysis of the time course of pressure change in the gas chamber, the dependency of the gas flow rate into the gas chamber and the chamber volume on the polytropic coefficient of gas in the gas chamber was discussed. To simulate the Bubble Formation at a single nozzle in a viscous medium having yield stress, the non-spherical Bubble Formation model was proposed. The calculated Bubble volumes agreed relatively well with the experimental ones.
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SO2 Bubble Formation at an Orifice Submerged in Water
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 1999Co-Authors: Koichi Terasaka, Yukiko Hieda, Hideki TsugeAbstract:To estimate mass transfer rate during Bubble Formation at an orifice, a theoretical model is proposed for soluble gas Bubble Formation in liquid by modifying the non-spherical Bubble Formation model. The absorption rate from pure SO2 gas Bubble to water is experimentally measured as well as Bubble shape and growth rate. Mass transfer from the gas-liquid interface during Bubble growth is described well by the penetration theory. Experimental Bubble shape, Bubble volume at its detachment from an orifice, growth rate and mass transfer rate are estimated well by the present model.
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Behavior of Bubble Formation at elevated pressure
Journal of Chemical Engineering of Japan, 1998Co-Authors: Koichi Terasaka, Hideki TsugeAbstract:In this study, Bubble Formation in high pressure systems is investigated. The volume and shape of Bubbles formed at an orifice submerged in liquid under high pressure are experimentally measured. To elucidate the Bubble Formation mechanism and to estimate the Bubble volume in high pressure systems, a non-spherical Bubble Formation model is used. When the volume and shape of the Bubble are calculated by the model under highly pressurized conditions, surface tension should be considered as a function of system pressure. The volume and shape of Bubble are estimated relatively well by the model, including the change in surface tension with the system pressure.
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Bubble Formation in flowing liquid under reduced gravity
Chemical Engineering Science, 1997Co-Authors: Hideki Tsuge, Koichi Terasaka, Yuko Tanaka, Hirokazu MatsueAbstract:Abstract A great deal of research has been done regarding Bubble Formation from submerged orifices in liquids under the force of gravity for the design of gas-liquid or gas-liquid-solid contacting equipment. On the other hand, little research has been done concerning Bubble Formation under reduced gravity conditions. For the basic design of the chemical process systems or life-support systems in space stations and on other planets, it is important to clarify the effects of various factors on the volume and shape of Bubbles formed at submerged orifices or nozzles under reduced gravity conditions. In order to disperse adequately Bubbles in liquids for mass transfer or chemical reaction processes at relatively low gas flow rates under reduced gravity, it is necessary to force Bubbles to become detached from nozzles by external forces. In this study, the liquid flow was used as the external force on Bubble Formation. The aim of this study is to clarify the behavior of Bubble Formation in flowing liquids under reduced gravity conditions. We experimentally investigated the effects of gas flow rate, liquid flow velocity, and liquid flow direction (cocurrent, countercurrent or cross-current flow) on Bubble Formation for a period of 1.2 s under reduced gravity conditions that were produced in the 10 m drop tower at the Hokkaido National Industrial Research Institute at Sapporo in Hokkaido. In order to describe theoretically the Bubble Formation in flowing liquids under reduced gravity conditions, a revised non-spherical Bubble Formation model was proposed and the calculated results of the Bubble volume were compared with the experimental ones.
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Bubble Formation at orifice in viscoelastic liquids
AIChE Journal, 1997Co-Authors: Koichi Terasaka, Hideki TsugeAbstract:To evaluate the effect of viscoelasticity on Bubble Formation, four rheological parameters of viscoelastic liquids were defined and measured by a rheometer. The effects of operating conditions and concentration of polyacrylamide aqueous solutions (PAA) as viscoelastic liquids on Bubble volume and the growth curve were experimentally measured. A high-speed video camera showed that the shapes of a Bubble growing in vis-coelastic liquids are not spherical. In this study, a nonspherical Bubble Formation model was proposed to theoretically estimate the volume, shape and growth curve of Bubbles formed from an orifice submerged in viscoelastic liquids which are assumed to follow Maxwell's viscoelastic model. This experimental results in relatively low concentrations of PAA, as well as previous researchers' results, agreed relatively well with the calculated ones by this model.
Reginald B. H. Tan - One of the best experts on this subject based on the ideXlab platform.
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Theoretical Analysis of Bubble Formation in a Co-Flowing Liquid
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 2002Co-Authors: W.b Chen, Reginald B. H. TanAbstract:A realistic non-spherical model for Bubble Formation in a co-flowing liquid is presented. In the model, an interfacial element approach is applied to describe the dynamics of Bubble Formation. The effect of flowing liquid velocity is modeled by a combination of the Bubble axis translation and liquid pressure analysis of each interfacial element. The Bubble shapes during Formation are predicted reasonably well by the present model. The effects of liquid velocity, gas flow rate, nozzle radius and gas chamber volume on the Bubble growth rates are studied. The model predictions are compared with the experimental data in literature and show good agreement.
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A non-spherical model for Bubble Formation with liquid cross-flow
Chemical Engineering Science, 2000Co-Authors: Reginald B. H. Tan, W.b Chen, K.h TanAbstract:A non-spherical model for Bubble Formation at an orifice with liquid cross-flow has been developed. The interface element approach is applied to describe the dynamics of Bubble Formation. The effect of liquid cross-flow on the Bubble Formation process is modelled by a combination of tilting of the Bubble axis and liquid pressure analysis of each element on the Bubble interface. Model predictions compare well with the experimental results available in the literature for different conditions of gas flow rate, orifice diameter and liquid cross-flow velocity. Simulated Bubble shapes are highly non-spherical, especially at high liquid velocities, and bear a striking resemblance with the experimental high-speed video sequences.
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A model for Bubble Formation and weeping at a submerged orifice
Chemical Engineering Science, 2000Co-Authors: Wenxing Zhang, Reginald B. H. TanAbstract:A theoretical model for Bubble Formation and weeping has been developed. Potential flow theory is used to describe Bubble Formation at the orifice. The influence of detached, rising Bubbles on liquid pressure at the orifice is predicted by Oseen's modification to potential flow. Model predictions of Bubble volumes, weeping flow rates and weep points agree well with experimental results.
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Modelling of Bubble Formation with Phase Change at a Submerged Nozzle
2000Co-Authors: W.b Chen, Reginald B. H. TanAbstract:A non-spherical model for Bubble Formation coupled with phase change at a submerged nozzle in a flowing subcooled liquid is presented. The interface element approach is applied to describe the dynamics of Bubble Formation. The results computed from present model are compared with the experimental data in the literature as well as with the results computed from other models. The results are in good agreement and show a significant improvement over other models.
Taotao Fu - One of the best experts on this subject based on the ideXlab platform.
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Bubble Formation and breakup dynamics in microfluidic devices a review
Chemical Engineering Science, 2015Co-Authors: Taotao FuAbstract:Abstract Bubbles are always encountered for gas–liquid two-phase flow in microchannels, and have potential applications in chemical engineering, polymer engineering, food engineering, and biological engineering. The Bubble Formation and breakup dynamics in microfluidic devices are reviewed in this article. The effects of the confinement of microchannels and the fluid flow on Bubble Formation and breakup dynamics are highlighted. The dynamical evolution of the gas–liquid interface during Bubble Formation and breakup in confined spaces is analyzed. The manipulation for the Bubble Formation and breakup in microfluidic devices is presented. The scaling laws for the Bubble size in such devices are also reviewed. Finally, the key issues for the scaling-up of Bubble generation in microfluidic devices are demonstrated.
Jianzhong Lin - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of Bubble Formation in highly viscous liquid in co-flowing microfluidic device
Microfluidics and Nanofluidics, 2019Co-Authors: Lin Xiaohui, Fubing Bao, Zhaoqin Yin, Gao Xiaoyan, Jianzhong LinAbstract:In this work, the dynamics of Bubble Formation in a highly viscous liquid in a co-flowing microfluidic device is experimentally investigated. The evolution of gaseous thread in the co-flowing device is recorded using a high-speed camera. The Bubble Formation process can be divided into three stages: retraction stage, expansion stage, and collapse stage. According to an analysis of the forces acting on the gaseous thread, the Bubble Formation in the co-flowing device is a competitive result of the surface tension, pressure difference and shearing effects. The surface tension effect plays an important role in the retraction stage. In the expansion stage, the pressure difference effect dominates the Bubble’s growth. While in the collapse stage, the shearing effect leads to the interface breakup. Three empirical correlations are proposed according to the experimental data and can be used to predict Bubble Formation frequency, the diameter and length of the generated Bubbles.
