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THE breakup AND ATOMIZATION OF A VISCOUS LIQUID JET

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Acta Mechanica Sinica 1996年第2期12卷 124-134页

作者：易世君解茂昭陈白欣 Dept.of Power Engineering Dalian Univ.of TechnologyDalian116023China

Based on the linear analysis of stability, a dispersion equation is deduced which delineates the evolution of a general 3-dimensional disturbance on the free surface of an incompressible viscous liquid jet, With respect to the spatial growing disturbance mode, the numerical results obtained from the solution of the dispersion equation reveal that a dimensionless parameter J(e) exists. As J(e) > 1, the axisymmetric disturbance mode is most unstable; and when J(e) breakup of a low-speed liquid jet results from the developing of axisymmetric disturbances, whose instability is produced by the surface tension; while the atomization of a high-speed Liquid jet is brought about by the evolution of nonaxisymmetric disturbance, whose instability is caused by the aerodynamic force on the interface between the jet and the ambient gas.

关键词： jet stability breakup atomization

Experimental study of the dissipation of supersaturated TDG during the jet breakup process

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Journal of Hydrodynamics 2019年第4期31卷 760-766页

作者： Hong-cheng Xue Qian Ma Ran Li Ming-jun Diao David Z. Zhu Jing-ying Lu State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065 China Southwest Hydraulic Institute for Waterways Chongqing Jiaotong University Chongqing 400016 China Department of Civil and Environmental Engineering University of Alberta Edmonton Canada

Elevated levels of the total dissolved gas (TDG) may occur downstream the dams during the spill process to increase the incidence of the gas bubble disease for fish. With increasing numbers of cascade hydropower stations being constructed or planned, the cumulative effects of the TDG supersaturation become an increasingly prominent issue. Previous studies of the supersaturated TDG mainly focused on the generation process in the stilling basin downstream the dam while ignoring the saturation changes during the jet breakup process by assuming a 100% plunge-in-level. This assumption may lead to errors in the TDG generation predictions and the scientific assessments of the TDG supersaturation. Therefore, in this paper, physical experiments are conducted to analyze the dissipation of the supersaturated TDG in the jet breakup process, and to establish a quantitative relation between the initial TDG level and the detention time of the jet in the air. These results indicate how the supersaturated TDG generated by an upstream dam affects the TDG generation and provide a scientific support for accurate predictions of the supersaturated TDG generation for high dam spills.

关键词： Jet breakup total dissolved gas (TDG) supersaturation high dam initial saturation dissipation

Paleogene marine deposition records of rifting and breakup of the South China Sea:An overview

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Science China Earth Sciences 2017年第12期60卷 2128-2140页

作者： LI QianYu WU GuoXuan ZHANG LiLi SHU Yu SHAO Lei State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Shenzhen Branch of China National Offshore Oil Corporation Guangzhou 510240China

A compilation of available marine deposition data from offshore S-SE China reveals evidence of rifting and breakup of the South China Sea(SCS) during the Paleogene. Marine deposition started earlier in the Paleocene in the East China Sea(ECS)-Taiwan region before expanding southwestward into the SCS region in the middle Eocene. Our data indicate the existence of an elongated Paleogene China Sea in these areas stretching along the northeasterly structural belts, probably as part of the marginal western paleo-Pacific. The southwestward shift of marine influence in the middle Eocene was responding to a period of intensive rifting and subsidence in the SCS region, while the sea in the ECS-Taiwan region started to shrink and shoal after the late Eocene, likely associated with local breakup and initial spreading in the Taiwan-Taixinan Basin area. The accumulation of hemipelagic sediments at ODP 1148 and IODP U1435 from near the continent-ocean boundary and at many other shelf-slope sites was in response to a large-scale breakup 34 to 33 Ma ago, subsequently leading to the birth of the SCS in the Oligocene.

关键词： Paleogene South China Sea East China Sea Marine deposition Tectonic implication breakup

Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons

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Science China(Physics,Mechanics & Astronomy) 2010年第4期53卷 672-679页

作者： MA Jun 1,2, TANG Jun 2 , ZHANG AiHua 3 & JIA Ya 2 1 Department of Physics, Lanzhou University of Technology, Lanzhou 730050, China 2 Department of Physics, Central China Normal University, Wuhan 430079, China 3 College of Electrical and Information Engineering, Lanzhou University of Technology, Lanzhou 730050, China Department of Physics Lanzhou University of Technology Lanzhou China Department of Physics Central China Normal University Wuhan China College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou China

The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise.

关键词： spiral wave factor of synchronization breakup multiplicative noise robustness

Numerical simulation of bubble breakup phenomena in anarrow flow field

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Applied Mathematics and Mechanics(English Edition) 2010年第4期31卷 449-460页

作者：张阿漫倪宝玉宋炳月姚熊亮 School of Shipbuilding Engineering Harbin Engineering University

Based on the boundary integral method, a 3D bubble breakup model in a narrow flow field is established, and a corresponding computation program is developed to simulate the symmetrical and asymmetrical bubble breakup. The calculated results are compared with the experimental results and agree with them very well, indicating that the numerical model is valid. Based on the basic behavior of bubbles in a narrow flow field, the symmetrical and asymmetrical bubble breakup is studied systematically using the developed program. A feasibility rule of 3D bubble breakup is presented. The dynamics of sub-bubbles after splitting is studied. The influences of characteristic parameters on bubble breakup and sub-bubble dynamics are analyzed.

关键词： bubble breakup narrow flow field sub-bubble narrow jet

Two-Dimensional Lattice Boltzmann Model for Droplet Impingement and breakup in Low Density Ratio Liquids

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Communications in Computational Physics 2011年第8期10卷 767-784页

作者： Amit Gupta Ranganathan Kumar Department of Mechanical Engineering Indian Institute of TechnologyNew DelhiIndia 110016 Department of Mechanical Materials and Aerospace EngineeringUniversity of Central FloridaOrlandoFL 32816USA

A two-dimensional lattice Boltzmann model has been employed to simulate the impingement of a liquid drop on a dry surface.For a range of Weber number,Reynolds number and low density ratios,multiple phases leading to breakup have been obtained.An analytical solution for breakup as function of Reynolds and Weber number based on the conservation of energy is shown to match well with the simulations.At the moment breakup occurs,the spread diameter is maximum;it increases with Weber number and reaches an asymptotic value at a density ratio of 10.Droplet breakup is found to be more viable for the case when the wall is non-wetting or neutral as compared to a wetting surface.Upon breakup,the distance between the daughter droplets is much higher for the case with a non-wetting wall,which illustrates the role of the surface interactions in the outcome of the impact.

关键词： Lattice Boltzmann droplet impingement spread factor breakup

Experimental study of the 9Li breakup reaction on Pb target

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Nuclear Science and Techniques 2017年第12期28卷 226-230页

作者： Wei-Hu Ma Jian-Song Wang Yan-Yun Yang Shi-Lun Jin Jun-Bing Ma Peng Ma D.Patel Xing-Quan Liu Zhen Bai Mei-Rong Huang Qiang Hu Zhi-Hao Gao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Lanzhou University Lanzhou 730000China

The breakup reaction of ~9Li on a Pb target has been measured at 32.7 MeV/nucleon for the first time. Two peaks of ~6He+t coincident fragments at 9.8 and 12.5 MeV were observed and agreed with the results of the generator coordinate method calculation. The experiment was carried out thanks to a specially arranged detection system around zero degrees at the Heavy Ion Research Facility in Lanzhou, Radioactive Ion Beam Line in Lanzhou(HIRFL–RIBLL).

关键词： breakup reaction Nuclear cluster states Invariant mass method

breakup of spiral wave under different boundary conditions

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Chinese Physics B 2007年第4期16卷 1159-1166页

作者：赵英奎王光瑞陈式刚 Graduate School of China Academy of Engineering Physics Beijing 100088 China Center for Nonlinear Studies Institute of Applied Physics and Computational Mathematics Beijing 100088 China

In this paper, we investigate the breakup of spiral wave under no-flux, periodic and Dirichlet boundary conditions respectively. When the parameter ε is close to a critical value for Doppler-induced wave breakup, the instability of the system caused by the boundary effect occurs in the last two cases, resulting in the breakup of spiral wave near the boundary. With our defined average order measure of spiral wave （AOMSW）, we quantify the degree of order of the system when the boundary-induced breakup of spiral wave happens. By analysing the AOMSW and outer diameter R of the spiral tip orbit, it is easy to find that this boundary effect is correlated with large values of R, especially under the Dirichlet boundary condition. This correlation is nonlinear, so the AOMSW sometimes oscillates with the variation of ε.

关键词： spiral breakup boundary reaction-diffusion

Contrasting Historical and Recent breakup Styles on the Meade River of Arctic Alaska in the Context of a Warming Climate

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American Journal of Climate Change 2013年第2期2卷 165-172页

作者： Richard A. Beck Kenneth M. Hinkel Wendy R. Eisner Douglas Whiteman Christopher D. Arp Richard Machida Chris Cuomo Hongxing Liu Changjoo Kim Andrew J. Rettig Chantal Ivenso Bo Yang Qiusheng Wu Haibin Su Shujie Wang Karen Frey John D. Lenters Brittany L. Potter Atmospheric Radiation Measurement Program Atqasuk USA Department of Geography Clark University Worcester USA Department of Geography University of Cincinnati Cincinnati USA Department of GeogSchool of Natural Resources University of Nebraska at Lincoln Lincoln USA raphy Clark University Worcester USA Department of Philosophy University of Georgia Athens USA Department of Physics and Geosciences Texas A&M University-Kingsville Kingsville USA Information Technology University of Alaska at Fairbanks Fairbanks USA School of Natural Resources University of Nebraska at Lincoln Lincoln USA Water and Environmental Research Center University of Alaska Fairbanks USA

Although data for temporal spring river ice breakup are available for a number of Arctic rivers, there is a paucity of information related to the type of breakup. The Arctic Climate Impact Assessment (ACIA) of 2005 predicted a transition from mechanical to thermal spring breakup of ice cover on arctic rivers, with this shift being greatest in exclusively Arctic watersheds where observed warming is most pronounced. We describe a rare instance of an entirely Arctic river with limited but well documented historical and recent data regarding the type of breakup. Time-series ground imagery of spring breakup from 1966, 1975, 1978, 2009, 2010 and 2012, incombination with interviews of local inhabitants, documents a shift from predominantly mechanical to predominantly thermal breakup after spring 1978 and by spring 2009 within the context of a locally and regionally warming Arctic. The resultant shift from predominantly mechanical to predominantly thermal breakup is predicted to result in significant changes to water, sediment, nutrient and organic carbon fluxes, as well as riparian ecology and human activities.

关键词： Arctic Alaska Climate Change Meade River Thermal breakup Mechanical breakup Ice Snow