Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019030520
A. Fedoseev, G. Sukhinin, I. Yarygin, V. Prikhodko, S. Novopashin
The influence of vacuum on a spherical clay sample is investigated via numerical simulation and experiment. The temporal and radial dependences of the temperature and mass of these samples were measured in the vacuum drying process. The numerical model in which the measurements were conducted calculates the moisture and heat transfer equations, where the effective coefficients of thermal conductivity and diffusion were set equal to the coefficients of a moist porous medium. Calculations were performed for various initial and boundary conditions. The data obtained on the temperature and moisture content distributions had sufficient deviations from the experimental data; however, both described important qualitative distribution features. The results of the current paper will help in determining the conditions of effective clay disintegration, which will facilitate the extraction of gold from gold-bearing clays.
{"title":"VACUUM PROCESSING OF GOLD-BEARING CLAY MATERIALS","authors":"A. Fedoseev, G. Sukhinin, I. Yarygin, V. Prikhodko, S. Novopashin","doi":"10.1615/interfacphenomheattransfer.2019030520","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019030520","url":null,"abstract":"The influence of vacuum on a spherical clay sample is investigated via numerical simulation and experiment. The temporal and radial dependences of the temperature and mass of these samples were measured in the vacuum drying process. The numerical model in which the measurements were conducted calculates the moisture and heat transfer equations, where the effective coefficients of thermal conductivity and diffusion were set equal to the coefficients of a moist porous medium. Calculations were performed for various initial and boundary conditions. The data obtained on the temperature and moisture content distributions had sufficient deviations from the experimental data; however, both described important qualitative distribution features. The results of the current paper will help in determining the conditions of effective clay disintegration, which will facilitate the extraction of gold from gold-bearing clays.","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74747889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2020033359
T. Lyubimova, O. Goncharova, A. Kupershtokh
This issue is devoted to the problems of Multiphase Flows and Heat/Mass Transfer. Three papers included in this issue concern the theoretical investigations on the behavior of n onu iform hydrodynamical systems under the action of time-dependent external fields. The effects of pulsating pr essure field, external mechanical vibrations, and alternat ing electric field are discussed. In the paper by A.A. Alabuzhev, the dynamics of a cylindrical g seous bubble surrounded by a coaxial layer of incompressible fluid of different density and bounded in t he axial direction by parallel rigid plates with different properties are studied. The system is subjected to the pulsa ting pressure field. Velocity of three-phase contact line motion is assumed to be proportional to the contact angle dev iations. It is shown that, in some parameter ranges, the frequency of volume oscillations can be close to zero. If thi s frequency is close to one of the frequencies of shape oscillations, then a double resonance response is observed that leads the unlimited growth of oscillation amplitude independently of the coefficient of eigen-oscillation damp ing. E.S. Sadilov discusses the effect of normal vibrations on th e stability of a three-layer system of fluids in zero gravity conditions. It is found that, when the ratio of exter nal layer thicknesses tends to unity the critical vibration amplitude for subharmonic instability mode tends to infinit y, which means the disappearance of subharmonic instability mode for the external layers of equal thicknesses. Synch ronous instability mode exists at any ratio of the external layer thicknesses. The work “Electroconvection Instability of Poorly Conduct ing Fluid in Alternating Electric Field,” by N.N. Kartavykh and O.O. Nekrasov, deals with the study of a flat horizo ntal layer of a poorly conducting fluid subjected to the alternating electric field and heating from above. The el ectroconductive instability mechanism is analyzed. On the basis of the linear analysis, a map of the stability of a condu ctive state of nonuniformly poorly heated conducting fluid is plotted and the dependence of the critical wave numbers on the electric field frequency is obtained. Quasiperiodic, synchronous, and chaotic oscillation regimes are found as a re ult of the nonlinear system dynamics analysis. The domains of coexistence of oscillatory modes with different intensities of flows are found. In the work “Investigation of the Isothermal Rheokinetic Po lymerization of the Epoxy Oligomer,” by V.G. Gilev, V.S. Chudinov, S.V. Rusakov, and A.V. Kondyurin, an experim ental study and numerical simulations of the kinetics of polymerization of the epoxy oligomer were carried out. Nume rical analysis of the kinetic dependencies of viscosity allows one to estimate the reaction rate constants of the pol ymerization process, which makes it possible to predict the properties of the polymer during its formation. It is shown t hat the results of viscosity measur
这期研究的是多相流和传热传质问题。本文收录了三篇论文，对非均形流体动力系统在时变外场作用下的行为进行了理论研究。讨论了脉动压力场、外部机械振动和交变电场的影响。a . a . Alabuzhev研究了由不同密度的不可压缩流体组成的同轴层包围的圆柱形气泡的动力学，并在轴向上用不同性质的平行刚性板作界。系统受到脉冲压力场的作用。假定三相接触线运动速度与接触角位移成正比。结果表明，在某些参数范围内，体积振荡的频率可以接近于零。如果该频率接近形状振荡的一个频率，则观察到双共振响应，导致振荡幅度无限增长，而不受本征振荡阻尼系数的影响。E.S. Sadilov讨论了正常振动对零重力条件下三层流体系统稳定性的影响。研究发现，当外层厚度比趋于一致时，亚谐波失稳模态的临界振动幅值趋于无穷大，这意味着等厚度外层的亚谐波失稳模态消失。同步失稳模式存在于任意外膜厚度比下。N.N. Kartavykh和O.O. Nekrasov的著作《交变电场中导电性差的流体的电对流不稳定性》研究了受交变电场和上方加热作用的导电性差流体的平坦水平层。分析了电导不稳定机理。在线性分析的基础上，绘制了非均匀差热导电流体的导电状态稳定性图，得到了临界波数与电场频率的关系。通过非线性动力学分析，得到了系统的准周期、同步和混沌振动状态。找到了不同流强度下振动模态共存的区域。在由V.G. Gilev, V.S. Chudinov, S.V. Rusakov和A.V. Kondyurin撰写的“环氧低聚物的等温流变动力学Po聚合研究”中，进行了环氧低聚物聚合动力学的实验研究和数值模拟。对黏度的动力学依赖性进行数值分析，可以估计聚合过程的反应速率常数，从而可以预测聚合物在形成过程中的性质。结果表明，粘度测量的结果不仅可以很好地跟踪粘合剂的固化过程，而且可以跟踪粘合剂的固化过程。K. Schweikert, a . Sielaff和P. Stephan的文章，“他在过热基材浸涂期间的通量”，致力于基于过热基材浸涂过程中温度测量的瞬态热流密度计算。采用高分辨率红外热像仪测量固体衬底的表面温度。然后，将得到的数值作为一个边界条件用于过热基板与流体交界面处的模拟。两种蒸发模式，即接触线蒸发和微层蒸发，在总热通量的大小上有明显的区别。M. Alekseev, I. Vozhakov和S. Lezhnin对过热流体从管道通道向封闭体的流出进行了数值模拟。模拟是在均匀单速度模型的基础上进行的。得到了压力、速度和s含量在体积中的分布。结果表明，管道与对面壁面之间的距离对压力和蒸汽含量达到准平稳值的时间有影响。在T. Gambaryan-Roisman的作品《沟槽基底上液体的同时吸收和蒸发》中，从理论上和理论上描述了纹理表面上的流体动力学、热量和质量传递过程
{"title":"PREFACE TO SPECIAL ISSUE MULTIPHASE FLOWS AND HEAT/MASS TRANSFER","authors":"T. Lyubimova, O. Goncharova, A. Kupershtokh","doi":"10.1615/interfacphenomheattransfer.2020033359","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2020033359","url":null,"abstract":"This issue is devoted to the problems of Multiphase Flows and Heat/Mass Transfer. Three papers included in this issue concern the theoretical investigations on the behavior of n onu iform hydrodynamical systems under the action of time-dependent external fields. The effects of pulsating pr essure field, external mechanical vibrations, and alternat ing electric field are discussed. In the paper by A.A. Alabuzhev, the dynamics of a cylindrical g seous bubble surrounded by a coaxial layer of incompressible fluid of different density and bounded in t he axial direction by parallel rigid plates with different properties are studied. The system is subjected to the pulsa ting pressure field. Velocity of three-phase contact line motion is assumed to be proportional to the contact angle dev iations. It is shown that, in some parameter ranges, the frequency of volume oscillations can be close to zero. If thi s frequency is close to one of the frequencies of shape oscillations, then a double resonance response is observed that leads the unlimited growth of oscillation amplitude independently of the coefficient of eigen-oscillation damp ing. E.S. Sadilov discusses the effect of normal vibrations on th e stability of a three-layer system of fluids in zero gravity conditions. It is found that, when the ratio of exter nal layer thicknesses tends to unity the critical vibration amplitude for subharmonic instability mode tends to infinit y, which means the disappearance of subharmonic instability mode for the external layers of equal thicknesses. Synch ronous instability mode exists at any ratio of the external layer thicknesses. The work “Electroconvection Instability of Poorly Conduct ing Fluid in Alternating Electric Field,” by N.N. Kartavykh and O.O. Nekrasov, deals with the study of a flat horizo ntal layer of a poorly conducting fluid subjected to the alternating electric field and heating from above. The el ectroconductive instability mechanism is analyzed. On the basis of the linear analysis, a map of the stability of a condu ctive state of nonuniformly poorly heated conducting fluid is plotted and the dependence of the critical wave numbers on the electric field frequency is obtained. Quasiperiodic, synchronous, and chaotic oscillation regimes are found as a re ult of the nonlinear system dynamics analysis. The domains of coexistence of oscillatory modes with different intensities of flows are found. In the work “Investigation of the Isothermal Rheokinetic Po lymerization of the Epoxy Oligomer,” by V.G. Gilev, V.S. Chudinov, S.V. Rusakov, and A.V. Kondyurin, an experim ental study and numerical simulations of the kinetics of polymerization of the epoxy oligomer were carried out. Nume rical analysis of the kinetic dependencies of viscosity allows one to estimate the reaction rate constants of the pol ymerization process, which makes it possible to predict the properties of the polymer during its formation. It is shown t hat the results of viscosity measur","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72641005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019030489
A. Safonov, N. Timoshenko, D. Panin
THE USE OF MOLYBDENUM ACTIVATOR FOR DEPOSITION OF FLUOROPOLYMER COATINGS WITH DIFFERENT STRUCTURES BY THE HOT WIRE CHEMICAL VAPOR DEPOSITION METHOD Alexey I. Safonov,1,2,∗ Denis Y. Panin,1 & Nikolay I. Timoshenko1 1Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev Ave. 1, 630090, Novosibirsk, Russia 2Novosibirsk State University, Pirogova Str. 2, 630090, Novosibirsk, Russia
钼活化剂在热丝化学气相沉积法沉积不同结构含氟聚合物涂层中的应用Alexey I. Safonov,1,2, Denis Y. Panin,1 & Nikolay I. Timoshenko1 1 kutateladze俄罗斯科学院西伯利亚分院热物理研究所，Lavrentyev街1,630090，新西伯利亚，俄罗斯2新西伯利亚国立大学，Pirogova街2,630090，新西伯利亚
{"title":"THE USE OF MOLYBDENUM ACTIVATOR FOR DEPOSITION OF FLUOROPOLYMER COATINGS WITH DIFFERENT STRUCTURES BY THE HOT WIRE CHEMICAL VAPOR DEPOSITION METHOD","authors":"A. Safonov, N. Timoshenko, D. Panin","doi":"10.1615/interfacphenomheattransfer.2019030489","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019030489","url":null,"abstract":"THE USE OF MOLYBDENUM ACTIVATOR FOR DEPOSITION OF FLUOROPOLYMER COATINGS WITH DIFFERENT STRUCTURES BY THE HOT WIRE CHEMICAL VAPOR DEPOSITION METHOD Alexey I. Safonov,1,2,∗ Denis Y. Panin,1 & Nikolay I. Timoshenko1 1Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev Ave. 1, 630090, Novosibirsk, Russia 2Novosibirsk State University, Pirogova Str. 2, 630090, Novosibirsk, Russia","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81512826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019032623
Kai Schweikert, A. Sielaff, P. Stephan
We report transient heat flux calculations based on temperature measurements during dip-coating of a superheated substrate. During the withdrawal of the substrate from a pool of volatile liquid, a film of finite length forms on the substrate’s surface, locally reducing the substrate temperature due to evaporation. The surface temperature of the solid substrate is measured using high-resolution infrared thermography and used as a boundary condition to calculate the transient heat flux profiles at the interface between the superheated substrate and the fluid. The shapes of these heat flux profiles are analyzed with special focus on the local heat flux in the thin film region and near the three-phase contact line. It is shown how the heat flux in both regions is dependent on wall superheat and dewetting velocity. Two evaporation regimes, namely contact line evaporation and microlayer evaporation, can be clearly distinguished by their magnitude in overall heat flux. A temperature-dependent critical velocity separates both regimes. The local heat flux in the contact line region sharply increases, when the critical velocity is exceeded. Within the thin film, the local heat flux increases with growing wall superheat and decreases with growing dewetting velocity.
{"title":"HEAT FLUX DURING DIP-COATING OF A SUPERHEATED SUBSTRATE","authors":"Kai Schweikert, A. Sielaff, P. Stephan","doi":"10.1615/interfacphenomheattransfer.2019032623","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019032623","url":null,"abstract":"We report transient heat flux calculations based on temperature measurements during dip-coating of a superheated substrate. During the withdrawal of the substrate from a pool of volatile liquid, a film of finite length forms on the substrate’s surface, locally reducing the substrate temperature due to evaporation. The surface temperature of the solid substrate is measured using high-resolution infrared thermography and used as a boundary condition to calculate the transient heat flux profiles at the interface between the superheated substrate and the fluid. The shapes of these heat flux profiles are analyzed with special focus on the local heat flux in the thin film region and near the three-phase contact line. It is shown how the heat flux in both regions is dependent on wall superheat and dewetting velocity. Two evaporation regimes, namely contact line evaporation and microlayer evaporation, can be clearly distinguished by their magnitude in overall heat flux. A temperature-dependent critical velocity separates both regimes. The local heat flux in the contact line region sharply increases, when the critical velocity is exceeded. Within the thin film, the local heat flux increases with growing wall superheat and decreases with growing dewetting velocity.","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85599286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019031067
J. Hrabovský, C. Liberatore, I. Mirza, J. Sládek, J. Beranek, A. Bulgakov, N. Bulgakova
Jan Hrabovsky, Chiara Liberatore, Inam Mirza, Juraj Sladek, Jiri Beranek, Alexander V. Bulgakov, & Nadezhda M. Bulgakova HiLASE Centre, Institute of Physics of the Czech Academy of Sciences, 28, 252 41 Dolní Břežany, Czech Republic Faculty of Chemical Technology, University of Pardubice, Studentská 95, Pardubice, Czech Republic Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 2027/3, 121 16 Prague Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Trojanova 13, 120 00 Prague, Czech Republic S.S. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, 1 Lavrentyev Ave., Novosibirsk, 630090, Russia
Jan Hrabovsky, Chiara Liberatore, Inam Mirza, Juraj Sladek, Jiri Beranek, Alexander V. Bulgakov， & Nadezhda M. Bulgakova HiLASE中心，捷克科学院物理研究所，28,252 41 Dolní Břežany，捷克共和国Pardubice大学化学技术学院，studentsk 95, Pardubice，捷克共和国布拉格查尔斯大学数学和物理学院，Ke Karlovu 2027/3, 121俄罗斯科学院西伯利亚分院热物理研究所，新西伯利亚拉夫连季耶夫大街1号，俄罗斯，630090
{"title":"SURFACE STRUCTURING OF KAPTON POLYIMIDE WITH FEMTOSECOND AND PICOSECOND IR LASER PULSES","authors":"J. Hrabovský, C. Liberatore, I. Mirza, J. Sládek, J. Beranek, A. Bulgakov, N. Bulgakova","doi":"10.1615/interfacphenomheattransfer.2019031067","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019031067","url":null,"abstract":"Jan Hrabovsky, Chiara Liberatore, Inam Mirza, Juraj Sladek, Jiri Beranek, Alexander V. Bulgakov, & Nadezhda M. Bulgakova HiLASE Centre, Institute of Physics of the Czech Academy of Sciences, 28, 252 41 Dolní Břežany, Czech Republic Faculty of Chemical Technology, University of Pardubice, Studentská 95, Pardubice, Czech Republic Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 2027/3, 121 16 Prague Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Trojanova 13, 120 00 Prague, Czech Republic S.S. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, 1 Lavrentyev Ave., Novosibirsk, 630090, Russia","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73497374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019030977
E. Sadilov
{"title":"THE EFFECT OF NORMAL VIBRATIONS ON THE STABILITY OF A THREE-LAYER FLUID SYSTEM IN ZERO GRAVITY","authors":"E. Sadilov","doi":"10.1615/interfacphenomheattransfer.2019030977","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019030977","url":null,"abstract":"","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74219989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2020032777
V. Bekezhanova, V. Andreev, I. A. Shefer
An exact solution is derived in the frame of the creeping flow model to describe thermocapillary convection in a twolayer system with heat defect when the heat is transferred through the interface. The solution is characterized by the Hiemenz-type velocity and temperature distribution which is quadratic in the longitudinal coordinate. The heat defect is connected with changes in the internal energy of the interface caused by the action of thermocapillary forces on the transformation of the area and shape of the surface. A model linear problem is studied to estimate the impact of this effect on the formation of typical flow regimes and stability of these regimes. There is only a nonlinear term in the energy balance condition at the interface corresponding to the heat defect in the model problem. Depending on the values of a parameter defining the character of thermal load on the lower boundary of the system this problem may not have any solution, or it may have one or two exact solutions obtained in an explicit form. In the frame of the linear theory the stability of one of these exact solutions is investigated both taking into account the heat defect and under classical condition of heat balance at the interface setting an equality of heat fluxes on this surface. The interface position and velocity and temperature perturbation fields are calculated. With the decrease of the liquid layer thickness the changes in the internal energy of the interface can result in oscillations of the surface and saw-shaped deformations. Such behavior of the interface does not appear in the system without the heat defect.
{"title":"INFLUENCE OF HEAT DEFECT ON THE CHARACTERISTICS OF A TWO-LAYER FLOW WITH THE HIEMENZ-TYPE VELOCITY","authors":"V. Bekezhanova, V. Andreev, I. A. Shefer","doi":"10.1615/interfacphenomheattransfer.2020032777","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2020032777","url":null,"abstract":"An exact solution is derived in the frame of the creeping flow model to describe thermocapillary convection in a twolayer system with heat defect when the heat is transferred through the interface. The solution is characterized by the Hiemenz-type velocity and temperature distribution which is quadratic in the longitudinal coordinate. The heat defect is connected with changes in the internal energy of the interface caused by the action of thermocapillary forces on the transformation of the area and shape of the surface. A model linear problem is studied to estimate the impact of this effect on the formation of typical flow regimes and stability of these regimes. There is only a nonlinear term in the energy balance condition at the interface corresponding to the heat defect in the model problem. Depending on the values of a parameter defining the character of thermal load on the lower boundary of the system this problem may not have any solution, or it may have one or two exact solutions obtained in an explicit form. In the frame of the linear theory the stability of one of these exact solutions is investigated both taking into account the heat defect and under classical condition of heat balance at the interface setting an equality of heat fluxes on this surface. The interface position and velocity and temperature perturbation fields are calculated. With the decrease of the liquid layer thickness the changes in the internal energy of the interface can result in oscillations of the surface and saw-shaped deformations. Such behavior of the interface does not appear in the system without the heat defect.","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74387324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019030134
Rui Niu, Ming Pang
Bubbly suspensions widely exist in many industrial fields, and thus it is very important to deeply investigate the physical properties of bubbly suspensions for the design and improvement of industrial products. In the present investigations on bubbly suspensions, twoand three-dimensional numerical simulations were performed, in which the obtained results showed some differences. To obtain an accurate and reasonable understanding of physical phenomena, it is necessary to clarify the similarities and differences of the computational results between twoand three-dimensional computations. Therefore, twoand three-dimensional computations are simultaneously carried out in order to study the behavior of a single bubble suspended in a Newtonian fluid under simple shear using the volume of fluid method. The trends of bubble deformation and influence on wall shear stress are analyzed in detail. The present study shows that the difference between the twoand three-dimensional computational results is related to the capillary number (Ca). When Ca ≤ 0.6, the computational results, including the bubble deformation and influence on the wall stress, are similar in the two kinds of computations; however, when Ca > 0.6, the results of the twoand three-dimensional computations show great differences. In the two-dimensional simulation, when the capillary number is relatively large, the bubble stretches and rocks, leading to unstable deformation. Correspondingly, the wall shear stress fluctuates with the bubble deformation. In the three-dimensional simulation, tip streaming occurs in the bubble. However, the wall shear stress remains stable after tip streaming appears.
{"title":"COMPARISON ON BUBBLE DEFORMATION AND INFLUENCE ON WALL SHEAR STRESS IN SIMPLE SHEAR FLOW BETWEEN TWO- AND THREE-DIMENSIONAL COMPUTATIONS","authors":"Rui Niu, Ming Pang","doi":"10.1615/interfacphenomheattransfer.2019030134","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019030134","url":null,"abstract":"Bubbly suspensions widely exist in many industrial fields, and thus it is very important to deeply investigate the physical properties of bubbly suspensions for the design and improvement of industrial products. In the present investigations on bubbly suspensions, twoand three-dimensional numerical simulations were performed, in which the obtained results showed some differences. To obtain an accurate and reasonable understanding of physical phenomena, it is necessary to clarify the similarities and differences of the computational results between twoand three-dimensional computations. Therefore, twoand three-dimensional computations are simultaneously carried out in order to study the behavior of a single bubble suspended in a Newtonian fluid under simple shear using the volume of fluid method. The trends of bubble deformation and influence on wall shear stress are analyzed in detail. The present study shows that the difference between the twoand three-dimensional computational results is related to the capillary number (Ca). When Ca ≤ 0.6, the computational results, including the bubble deformation and influence on the wall stress, are similar in the two kinds of computations; however, when Ca > 0.6, the results of the twoand three-dimensional computations show great differences. In the two-dimensional simulation, when the capillary number is relatively large, the bubble stretches and rocks, leading to unstable deformation. Correspondingly, the wall shear stress fluctuates with the bubble deformation. In the three-dimensional simulation, tip streaming occurs in the bubble. However, the wall shear stress remains stable after tip streaming appears.","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79302846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019031185
I. Yarygin, V. Prikhodko, Yu.N. Vyazov
{"title":"SPECTROPHOTOMETRY TECHNIQUE FOR DROPLET PHASE SPATIAL DISTRIBUTION MEASUREMENTS IN GAS-DROPLET FLOW BEHIND A SUPERSONIC NOZZLE IN A VACUUM","authors":"I. Yarygin, V. Prikhodko, Yu.N. Vyazov","doi":"10.1615/interfacphenomheattransfer.2019031185","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019031185","url":null,"abstract":"","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85937907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1615/interfacphenomheattransfer.2019030611
O. Nekrasov, N. Kartavykh
The flat horizontal layer of the poorly conducting fluid is placed in the alternating electric field and heated from above. Its behavior is investigated in the electroconvection low-mode model. The approximation in which density and conductivity of the fluid are linearly dependent on temperature is used. Linear instability is analyzed by means of the Floquet theory. The system of eight differential equations, which describe the motion of the fluid, is integrated using the Runge-Kutta-Merson fourth-order method. The marginal stability curves are plotted in coordinates “wave number – nondimensional electric parameter.” The critical values of the wave number and the nondimensional electric parameter are determined for various external influence frequencies. The nonlinear regimes of the fluid flow are investigated at the critical value of the wave number. The fluid electroconvection flow intensity as a function of the nondimensional electric parameter is plotted. The various types of the oscillation regimes are discovered, and the competition regions of different electroconvection modes with various flow intensities are found.
{"title":"ELECTROCONVECTION INSTABILITY OF POORLY CONDUCTING FLUID IN ALTERNATING ELECTRIC FIELD","authors":"O. Nekrasov, N. Kartavykh","doi":"10.1615/interfacphenomheattransfer.2019030611","DOIUrl":"https://doi.org/10.1615/interfacphenomheattransfer.2019030611","url":null,"abstract":"The flat horizontal layer of the poorly conducting fluid is placed in the alternating electric field and heated from above. Its behavior is investigated in the electroconvection low-mode model. The approximation in which density and conductivity of the fluid are linearly dependent on temperature is used. Linear instability is analyzed by means of the Floquet theory. The system of eight differential equations, which describe the motion of the fluid, is integrated using the Runge-Kutta-Merson fourth-order method. The marginal stability curves are plotted in coordinates “wave number – nondimensional electric parameter.” The critical values of the wave number and the nondimensional electric parameter are determined for various external influence frequencies. The nonlinear regimes of the fluid flow are investigated at the critical value of the wave number. The fluid electroconvection flow intensity as a function of the nondimensional electric parameter is plotted. The various types of the oscillation regimes are discovered, and the competition regions of different electroconvection modes with various flow intensities are found.","PeriodicalId":44077,"journal":{"name":"Interfacial Phenomena and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82821573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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