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Characteristics of a bubble jet near a vertical wall
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作者 张阿漫 姚熊亮 李佳 《Journal of Marine Science and Application》 2008年第1期1-6,共6页
A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with ... A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with the basic phenomenon of the interaction between a bubble and a wall, the dynamics of bubbles near rigid walls were studied systematically with the program. Calculated results agreed well with experimental results. The relationship between the Bjerknes effect of a wall and characteristic parameters was then studied and the calculated results of various cases were compared and discussed with the Blake criterion based on the Kelvin-impulse theory. Our analyses show that the angle of the jet’s direction and the pressure on the rigid wall have a close relationship with collapse force and the bubble’s characteristic parameters. From this, the application range of Blake criterion can be determined. This paper aims to provide a basis for future research on the dynamics of bubbles near a wall. 展开更多
关键词 bubble jet rigid wall boundary integral Bjerknes effect Blake criterion
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Experimental Study on Effect of Inclination Angle on Bubble Collapse near Attached Air Bubble
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作者 WANG Jia-xia WU Shi-zeng +2 位作者 LIU Kun JIANG Ming-zuo WANG Zi-li 《China Ocean Engineering》 SCIE EI CSCD 2023年第5期753-767,共15页
Experiments were conducted to investigate the dynamics of an oscillating bubble generated by a spark in the presence of an inclined attached air bubble.The study primarily focused on the influence of the inclination a... Experiments were conducted to investigate the dynamics of an oscillating bubble generated by a spark in the presence of an inclined attached air bubble.The study primarily focused on the influence of the inclination angle on the behavior of bubble jetting orientation,air bubble shape modes,and motion characteristics of the interaction between the two bubbles.Various complex bubble jetting behaviors were observed,including the presence of multiple types of bubble jetting directions,bubble splitting,and multidirectional jets.Four types of air bubble shapes were defined,namely inclined cup cover-shaped(with and without splitting),double-peaked cup cover-shaped,and inclined L-shaped air bubbles.The formation of different types of bubble jets was analyzed using the vector synthesis principle of the Bjerknes force exerted by the inclined attached air bubble and a steel plate.To describe the diverse orientations of bubble jetting and air bubble shapes,new parameters namely the dimensionless spark bubble oscillation time T^(*)and volume ratio V^(*)that consider the inclination angle are proposed.The findings of this investigation contribute to the existing knowledge and have the potential to further enhance methods for mitigating cavitation damage in marine,hydraulic machinery systems,and medical fields.l fields. 展开更多
关键词 spark-generated bubble experiment inclination angle bubble jet air bubble shape bubble dynamics
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A boundary element method for the simulation of non-spherical bubbles and their interactions near a free surface 被引量:6
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作者 Zhang-Rui Li Lei Sun +1 位作者 Zhi Zong Jing Dong 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第1期51-65,共15页
The basic principle and numerical technique for simulating two three-dimensional bubbles near a free surface are studied in detail by using boundary element method. The singularities of influence coefficient matrix ar... The basic principle and numerical technique for simulating two three-dimensional bubbles near a free surface are studied in detail by using boundary element method. The singularities of influence coefficient matrix are eliminated using coordinate transformation and so-called 4π rule. The solid angle for the open surface is treated in direct method based on its definition. Several kinds of configurations for the bubbles and free surface have been investigated. The pressure contours during the evolution of bubbles are obtained in our model and can better illuminate the mechanism underlying the motions of bubbles and free surface. The bubble dynamics and their interactions have close relation with the standoff distances, buoyancy parameters and initial sizes of bubbles. Completely different bubble shapes, free surface motions, jetting patterns and pressure distributions under different parameters can be observed in our model, as demon- strated in our calculation results. 展开更多
关键词 Boundary element method- Singularities - Solid angle bubble jetting
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Jetting of a near-wall cavitation bubble induced by another tandem bubble
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作者 Hui Han Jing-zhu Wang +3 位作者 Jian-lin Huang Peng-bo Bai Yong-gang Chen Yi-wei Wang 《Journal of Hydrodynamics》 SCIE EI CSCD 2024年第3期444-456,共13页
Double bubbles near a rigid wall surface collapse to produce a significant jet impact,with potential applications in surface cleaning and ultrasonic lithotripsy.However,the dynamic behaviors of near-wall bubbles remai... Double bubbles near a rigid wall surface collapse to produce a significant jet impact,with potential applications in surface cleaning and ultrasonic lithotripsy.However,the dynamic behaviors of near-wall bubbles remain unexplored.In this study,we investigate the jetting of a near-wall bubble induced by another tandem bubble.We define two dimensionless standoff distances,γ_(1),γ_(2),to represent the distances from the center of the near-wall bubble to the rigid wall and the center of controlling bubble to the center of the near-wall bubble,respectively.Our observations reveal three distinct jetting regimes for the near-wall bubble:transferred jetting,double jetting,and directed jetting.To further investigate the jetting mechanism,numerical simulations are conducted using the compressibleInterFoam solver in the open-source framework of OpenFOAM.A detailed analysis shows that the transferred jet flow is caused by the pinch-off resulting from the axial contraction velocity at the lower end of the near-wall bubble being greater than the vertical contraction velocity,leading to a maximum jet velocity of 682.58 m/s.In the case of double jetting,intense stretching between the controlling bubble and the wall leads to a pinch-off and a double jetting with a maximum velocity of 1096.29 m/s.The directed jet flow is caused by the downward movement of the high-pressure region generated by the premature collapse of the controlling bubble,with the maximum jet velocity reaching 444.62 m/s. 展开更多
关键词 jetting of near-wall bubble controlling bubble impact velocity
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A pilot-scale jet bubbling reactor for wet flue gas desulfurization with pyrolusite 被引量:26
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作者 SU Shi-jun ZHU Xiao-fan +2 位作者 LIU Yong-jun JIANG Wen-ju JIN Yan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第5期827-831,共5页
MnO2 in pyrolusite can react with SO2 in flue gas and obtain by-product MnSO4· H2O. A pilot scale jet bubbling reactor was applied in this work. Different factors affecting both SO2 absorption efficiency and Mn2^... MnO2 in pyrolusite can react with SO2 in flue gas and obtain by-product MnSO4· H2O. A pilot scale jet bubbling reactor was applied in this work. Different factors affecting both SO2 absorption efficiency and Mn2^+ extraction rate have been investigated, these factors include temperature of inlet gas flue, ration of liquid/solid mass flow rate( L/S), pyrolusite grade, and SO2 concentration in the inlet flue gas. In the meantime, the procedure of purification of absorption liquid was also discussed. Experiment results indicated that the increase of temperature from 30 to 70 K caused the increase of SO2 absorption efficiency from 81.4% to 91.2%. And when SO2 concentration in the inlet flue gas increased from 500 to 3000 ppm, SO2 absorption efficiency and Mn2^+ extraction rate decreased from 98.1% to 82.2% and from 82.8% to 61.7%, respectively. The content of MnO2 in pyrolusite had a neglectable effect on SO2, absorption efficiency. Low L/S was good for both removal of SO2 and Mn2^+ extraction. The absorption liquid was filtrated and purified to remove Si, Mg, Ca, Fe, Al and heavy metals, last product MnSO4· H2O was obtained which quality could reach China GB1622-86, the industry grade standards. 展开更多
关键词 wet FGD jet bubbling reactor SO2 PYROLUSITE manganese sulfate
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Experimental determination of gas holdup and volumetric mass transfer coefficient in a jet bubbling reactor 被引量:3
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作者 Mostafa Abbasian-arani Mohammad Sadegh Hatamipour Amir Rahimi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第6期61-67,共7页
The hydrodynamics and mass transfer characteristics of a lab-scale jet bubbling reactor(JBR)including the gas holdup,volumetric mass transfer coefficient and specific interfacial area were assessed experimentally inve... The hydrodynamics and mass transfer characteristics of a lab-scale jet bubbling reactor(JBR)including the gas holdup,volumetric mass transfer coefficient and specific interfacial area were assessed experimentally investigating the influence of temperature,pH and superficial gas velocity.The reactor diameter and height were 11 and 30 cm,respectively.It was equipped with a single sparger,operating at atmospheric pressure,20 and 40℃,and two pH values of 3 and 6.The height of the liquid was 23 cm,while the superficial gas velocity changed within 0.010-0.040 m·s^(-1)range.Experiments were conducted with pure oxygen as the gas phase and saturated lime solution as the liquid phase.The liquid-side volumetric mass transfer coefficient was determined under unsteady-state oxygen absorption in a saturated lime solution.The gas holdup was calculated based on the liquid height change,while the specific interfacial area was obtained by a physical method based on the bubble size distribution(BSD)in different superficial gas velocities.The results indicated that at the same temperature but different pH,the gas holdup variation was negligible,while the liquid-side volumetric mass transfer coefficient at the pH value of 6 was higher than that at the pH=3.At a constant pH but different temperatures,the gas holdup and the liquid-side volumetric mass transfer coefficients at 40℃were higher than that of the same at 20℃.A reasonable and appropriate estimation of the liquid-side volumetric mass transfer coefficient(kla)in a pilot-scale JBR was provided which can be applied to the design and scale-up of JBRs. 展开更多
关键词 jet bubbling reactor Liquid-side volumetric mass transfer coefficient Gas holdup Specific interfacial area Experimental analysis
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Experimental investigation of the interaction between a pulsating bubble and a rigid cylinder 被引量:6
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作者 A-Man Zhang Wei Xiao Shi-Ping Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第4期503-512,共10页
In this paper, the behavior of a bubble near a rigid cylinder is studied experimentally as the positions of bubble induction change, and several cylinders with different diam- eters are used in the experiment. The mai... In this paper, the behavior of a bubble near a rigid cylinder is studied experimentally as the positions of bubble induction change, and several cylinders with different diam- eters are used in the experiment. The main results are as follows. The behavior of a bubble near a rigid cylinder is distinct from that near a rigid plate. When the cylinders are laid in deep water, there will occur three kinds of typical bubble shapes as the distance between bubble and cylinder increases. And the bubble shapes are different as the diam- eter of cylinder varies. When the cylinders are laid near a free surface, the behaviors of bubble near cylinders with dif- ferent diameters are similar. For a certain distance between bubble and free surface, as the distance between bubble and cylinder increases, "double jet", "inclined jet" and "down- ward jet" will take place successively. 展开更多
关键词 bubble ~ Cylinder. Electric spark- Free sur-face ~ jet
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Bubbling to Jetting Transition during Argon Injection in Molten Steel
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作者 Miguel A. Barron Joan Reyes Dulce Y. Medina 《World Journal of Engineering and Technology》 2020年第4期605-616,共12页
Bubbling to Jetting Transition is of the outmost importance in metallurgical processes given that the flow regime influences the refining rates, the refractory erosion, and the blockage of injection nozzles. Bubbling ... Bubbling to Jetting Transition is of the outmost importance in metallurgical processes given that the flow regime influences the refining rates, the refractory erosion, and the blockage of injection nozzles. Bubbling to jetting transition during subsonic bottom injection of argon in molten steel is studied here. The effect of the molten steel height, the injection velocity, the nozzle diameter, and the molten steel viscosity on the jet height and the bubbling to jetting transition is numerically analyzed using Computational Fluid Dynamics. Five subsonic argon injection velocities are considered: 5, 25, 50, 100 and 150 m/s. Three values of the metal height are taken into account, namely 1.5 m, 2 m and 2.5 m. Besides, three values of the nozzle diameters are considered: 0.001 m, 0.005 m and 0.01 m. Finally, three values of the molten steel viscosity are supposed: 0.0067, 0.1 and 1 kg/(m<span style="font-family:Verdana;"><span style="white-space:nowrap;">·</span></span><span style="font-family:Verdana;">s). It is observed that for the argon-molten steel system</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the bubbling to jetting transition occurs for an injection velocity less than 25 m/s and that for the range of viscosities considered, the molten steel viscosity does not exert significant influence on the jet height and the bubbling to jetting transition. Due to the jet instability at subsonic velocities</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> a second transition, namely jetting to bubbling, is appreciated</span><span style="font-family:Verdana;">.</span> 展开更多
关键词 Argon Injection Bubbling to jetting Transition CFD Injection Velocity jet Height Molten Steel Nozzle Diameter
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Recent progress on the jetting of single deformed cavitation bubbles near boundaries 被引量:3
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作者 Jing-zhu Wang Guang-hang Wang +1 位作者 Qing-yun Zeng Yi-wei Wang 《Journal of Hydrodynamics》 SCIE EI CSCD 2023年第5期832-857,共26页
Cavitation occurs widely in nature and engineering and is a complex problem with multiscale features in both time and space due to its associating violent oscillations. To understand the important but complicated phen... Cavitation occurs widely in nature and engineering and is a complex problem with multiscale features in both time and space due to its associating violent oscillations. To understand the important but complicated phenomena and fluid mechanics behind cavitation, a great deal of effort has been invested in investigating the collapse of a single bubble near different boundaries. This review aims to cover recent developments in the collapse of single bubbles in the vicinity of complex boundaries, including single boundaries and two parallel boundaries, and open questions for future research are discussed. Microjets are the most prominent features of the non-spherical collapse of cavitation bubbles near boundaries and are directed toward rigid walls and away from free surfaces. Such a bubble generally splits, resulting in the formation of two axial jets directed opposite to each other under the constraints of an elastic boundary or two parallel boundaries. The liquid jet penetrates the bubble, impacts the boundary, and exerts a great deal of stress on any nearby boundary. This phenomenon can cause damage, such as the erosion of blades in hydraulic machinery, the rupture of human blood vessels, and underwater explosions, but can also be exploited for applications, such as needle-free injection, drug and gene delivery, surface cleaning, and printing. Many fascinating developments related to these topics are presented and summarized in this review. Finally, three directions are proposed that seem particularly fruitful for future research on the interaction of cavitation bubbles and boundaries. 展开更多
关键词 jetting cavitation bubble near complex boundaries bubble-based technique and their applications
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Numerical analysis of bubble dynamics in the diffuser of a jet pump under variable ambient pressure 被引量:4
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作者 龙新平 王晴晴 +4 位作者 肖龙洲 章君强 徐茂森 吴伟烽 季斌 《Journal of Hydrodynamics》 SCIE EI CSCD 2017年第3期510-519,共10页
Recent studies have shown that the collapse of cavitation bubbles in a jet pump can generate an extremely high pressure with many potential applications. The dynamics of the bubble is governed by the Rayleigh-Plesset ... Recent studies have shown that the collapse of cavitation bubbles in a jet pump can generate an extremely high pressure with many potential applications. The dynamics of the bubble is governed by the Rayleigh-Plesset equation. With the bubble dynamics equation and the heat and mass transfer model solved with the Runge-Kutta fourth order adaptive step size method, the oscillations of the bubble in the diffuser of the jet pump are assessed under varied conditions. To obtain the pressure variation along the diffuser, the Bernoulli equation and the pressure measured in experiment are coupled. The results of simulation show that a transient motion of the bubbles can be obtained in the diffuser quantitatively, to obtain the pressure and temperature shock in the bubble. Moreover, increasing the outlet pressure coefficient would result in a more intense bubble collapsing process, which can be used in the subsequent studies of the cavitation applications. The predictions are compared with experiments with good agreement. 展开更多
关键词 Cavitation jet pump bubble collapse
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Oxygen transfer characteristics of bubbly jet in regular waves
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作者 Ze-gao Yin De-chun Liu +1 位作者 Yuan Li Yan-xu Wang 《Journal of Hydrodynamics》 SCIE EI CSCD 2020年第5期879-887,共9页
The dissolved oxygen level is an important index of the water environment,and in this paper,the oxygen transfer of the bubbly jet in regular waves is investigated numerically and experimentally.The Reynolds-averaged N... The dissolved oxygen level is an important index of the water environment,and in this paper,the oxygen transfer of the bubbly jet in regular waves is investigated numerically and experimentally.The Reynolds-averaged Navier-Stokes equations,the re-normalisation group k-e equations,and the volume of fluid(VOF)technique are used along with a 2-D CFD model to simulate the wave and bubble motions as well as the turbulence,and a dissolved oxygen transport equation is used to model the oxygen transfer behavior both through the bubbly interface and the wave surface.A series of experiments are conducted to validate the mathematical model,with good agreement.In addition,a group of dimensionless parameters are defined from the wave parameter and the aeration parameter,and their relationships with the total oxygen transfer coefficient are explored.Furthermore,the dimensional analysis and the least squares methods are used to derive simple prediction formulas for the total oxygen transfer coefficient,and they are validated with the related experimental data. 展开更多
关键词 Bubbly jet regular wave mathematical model total oxygen transfer coefficient
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