Статті в журналах: "Liquid bridge dynamics"

1

Teschke, Omar, David Mendez Soares, Whyllerson Evaristo Gomes, and Juracyr Ferraz Valente Filho. "Floating liquid bridge charge dynamics." Physics of Fluids 28, no. 1 (January 2016): 012105. http://dx.doi.org/10.1063/1.4938402.

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2

AKITOMO, Dai, Ichiro UENO, and Hiroshi KAWAMURA. "Dynamics of nano-scale liquid bridge." Proceedings of the Thermal Engineering Conference 2004 (2004): 155–56. http://dx.doi.org/10.1299/jsmeted.2004.155.

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3

Coelho, Rodrigo C. V., Luís A. R. G. Cordeiro, Rodrigo B. Gazola, and Paulo I. C. Teixeira. "Dynamics of two-dimensional liquid bridges." Journal of Physics: Condensed Matter 34, no. 20 (March 14, 2022): 205001. http://dx.doi.org/10.1088/1361-648x/ac594b.

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Abstract We have simulated the motion of a single vertical, two-dimensional liquid bridge spanning the gap between two flat, horizontal solid substrates of given wettabilities, using a multicomponent pseudopotential lattice Boltzmann method. For this simple geometry, the Young–Laplace equation can be solved (quasi-)analytically to yield the equilibrium bridge shape under gravity, which provides a check on the validity of the numerical method. In steady-state conditions, we calculate the drag force exerted by the moving bridge on the confining substrates as a function of its velocity, for different contact angles and Bond numbers. We also study how the bridge deforms as it moves, as parametrized by the changes in the advancing and receding contact angles at the substrates relative to their equilibrium values. Finally, starting from a bridge within the range of contact angles and Bond numbers in which it can exist at equilibrium, we investigate how fast it must move in order to break up.

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4

Vincent, L., L. Duchemin, and S. Le Dizès. "Forced dynamics of a short viscous liquid bridge." Journal of Fluid Mechanics 761 (November 18, 2014): 220–40. http://dx.doi.org/10.1017/jfm.2014.622.

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AbstractThe dynamics of an axisymmetric liquid bridge of a fluid of density ${\it\rho}$, viscosity ${\it\mu}$ and surface tension ${\it\sigma}$ held between two co-axial disks of equal radius $e$ is studied when one disk is slowly moved with a velocity $U(t)$. The analysis is performed using a one-dimensional model for thin bridges. We consider attached boundary conditions (the contact line is fixed to the boundary of the disk), neglect gravity and limit our analysis to short bridges such that there exists a stable equilibrium shape. This equilibrium is a Delaunay curve characterized by the two geometric parameters $\ell _{0}=V_{0}/({\rm\pi}e^{3})$ and $S=\ell ({\rm\pi}e^{2})/V_{0}$, where $V_{0}$ is the volume of fluid and $\ell$ the length of the bridge. Our objective is to analyse the departure of the dynamical solution from the static Delaunay shape as a function of $\ell _{0}$, $S$, the Ohnesorge number $Oh={\it\mu}/\sqrt{{\it\rho}{\it\sigma}e}$, and the instantaneous velocity $U(t)$ and acceleration $\partial _{t}U$ (non-dimensionalized using $e$ and ${\it\sigma}/{\it\rho}$) of the disk. Using a perturbation theory for small velocity and acceleration, we show that (i) a non-homogeneous velocity field proportional to $U(t)$ and independent of $Oh$ is present within the bridge; (ii) the area correction to the equilibrium shape can be written as $U^{2}A_{i}+U\,Oh\,A_{v}+\partial _{t}UA_{a}$ where $A_{i}$, $A_{v}$ and $A_{a}$ are functions of $\ell _{0}$ and $S$ only. The characteristics of the velocity field and the shape corrections are analysed in detail. For the case of a cylinder ($S=1$), explicit expressions are derived and used to provide some insight into the break-up that the deformation would induce. The asymptotic results are validated and tested by direct numerical simulations when the velocity is constant and when it oscillates. For the constant velocity case, we demonstrate that the theory provides a very good estimate of the dynamics for a large range of parameters. However, a systematic departure is observed for very small $Oh$ due to the persistence of free eigenmodes excited during the transient. These same eigenmodes also limit the applicability of the theory to oscillating bridges with large oscillating periods. Finally, the perturbation theory is applied to the cylindrical solution of Frankel & Weihs (J. Fluid Mech., vol. 155 (1985), pp. 289–307) obtained for constant velocity $U$ when the contact lines are allowed to move. We show that it can be used to compute the correction associated with acceleration. Finally, the effect of gravity is discussed and shown to modify the equilibrium shape but not the main results obtained from the perturbation theory.

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5

Zhang, X., R. S. Padgett, and O. A. Basaran. "Nonlinear deformation and breakup of stretching liquid bridges." Journal of Fluid Mechanics 329 (December 25, 1996): 207–45. http://dx.doi.org/10.1017/s0022112096008907.

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In this paper, the nonlinear dynamics of an axisymmetric liquid bridge held captive between two coaxial, circular, solid disks that are separated at a constant velocity are considered. As the disks are continuously pulled apart, the bridge deforms and ultimately breaks when its length attains a limiting value, producing two drops that are supported on the two disks. The evolution in time of the bridge shape and the rupture of the interface are investigated theoretically and experimentally to quantitatively probe the influence of physical and geometrical parameters on the dynamics. In the computations, a one-dimensional model that is based on the slender jet approximation is used to simulate the dynamic response of the bridge to the continuous uniaxial stretching. The governing system of nonlinear, time-dependent equations is solved numerically by a method of lines that uses the Galerkin/finite element method for discretization in space and an adaptive, implicit finite difference technique for discretization in time. In order to verify the model and computational results, extensive experiments are performed by using an ultra-high-speed video system to monitor the dynamics of liquid bridges with a time resolution of 1/12 th of a millisecond. The computational and experimental results show that as the importance of the inertial force – most easily changed in experiments by changing the stretching velocity – relative to the surface tension force increases but does not become too large and the importance of the viscous force – most easily changed by changing liquid viscosity – relative to the surface tension force increases, the limiting length that a liquid bridge is able to attain before breaking increases. By contrast, increasing the gravitational force – most readily controlled by varying disk radius or liquid density – relative to the surface tension force reduces the limiting bridge length at breakup. Moreover, the manner in which the bridge volume is partitioned between the pendant and sessile drops that result upon breakup is strongly influenced by the magnitudes of viscous, inertial, and gravitational forces relative to surface tension ones. Attention is also paid here to the dynamics of the liquid thread that connects the two portions of the bridge liquid that are pendant from the top moving rod and sessile on the lower stationary rod because the manner in which the thread evolves in time and breaks has important implications for the closely related problem of drop formation from a capillary. Reassuringly, the computations and the experimental measurements are shown to agree well with one another.

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6

Connell, Joseph, Murray Rudman, and Ranganathan Prabhakar. "Influence of volume and aspect ratio of liquid bridges on capillary breakup rheometry." Physics of Fluids 34, no. 3 (March 2022): 033105. http://dx.doi.org/10.1063/5.0084878.

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Capillary thinning of liquid bridges is routinely used for extensional rheology of Newtonian and complex fluids. Although it is expected that the volume and aspect ratio of a liquid bridge significantly influence its dynamics, the role played by these parameters in rheological characterization has not been previously studied. We perform numerical simulations of Newtonian as well as viscoelastic liquid bridges with the one-dimensional slender-filament approximation of Eggers and Dupont [“Drop formation in a one-dimensional approximation of the Navier–Stokes equation,” J. Fluid Mech. 262, 205–221 (1994)] and Ardekani et al. [“Dynamics of bead formation, filament thinning and breakup in weakly viscoelastic jets,” J. Fluid Mech. 665, 46–56 (2010)]. Sample volume and bridge aspect ratio control two phenomena that can adversely impact rheological characterization: the tendency to form satellite drops at the necking plane and the slowing down of capillary thinning due to the proximity (in parameter space) of the liquid-bridge stability boundary. The optimal range of these parameter values to avoid drop formation and slowdown is discussed.

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7

Dodds, Shawn, Marcio S. Carvalho, and Satish Kumar. "The dynamics of three-dimensional liquid bridges with pinned and moving contact lines." Journal of Fluid Mechanics 707 (August 2, 2012): 521–40. http://dx.doi.org/10.1017/jfm.2012.296.

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AbstractLiquid bridges with moving contact lines are relevant in a variety of natural and industrial settings, ranging from printing processes to the feeding of birds. While it is often assumed that the liquid bridge is two-dimensional in nature, there are many applications where either the stretching motion or the presence of a feature on a bounding surface lead to three-dimensional effects. To investigate this we solve Stokes equations using the finite-element method for the stretching of a three-dimensional liquid bridge between two flat surfaces, one stationary and one moving. We first consider an initially cylindrical liquid bridge that is stretched using either a combination of extension and shear or extension and rotation, while keeping the contact lines pinned in place. We find that whereas a shearing motion does not alter the distribution of liquid between the two plates, rotation leads to an increase in the amount of liquid resting on the stationary plate as breakup is approached. This suggests that a relative rotation of one surface can be used to improve liquid transfer to the other surface. We then consider the extension of non-cylindrical bridges with moving contact lines. We find that dynamic wetting, characterized through a contact line friction parameter, plays a key role in preventing the contact line from deviating significantly from its original shape as breakup is approached. By adjusting the friction on both plates it is possible to drastically improve the amount of liquid transferred to one surface while maintaining the fidelity of the liquid pattern.

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8

Shaikhitdinov R. Z. and Sharipov T. I. "Dynamics of liquid mass transfer in a water bridge." Technical Physics Letters 48, no. 6 (2022): 31. http://dx.doi.org/10.21883/tpl.2022.06.53461.19161.

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The paper presents experimental results of the dynamics of mass transfer through a water bridge arising between two dielectric cups with distilled water under the action of a constant high voltage between cylindrical electrodes. It is established that, depending on the ratio of the electrode diameters, the total fluid flow in the water bridge can be directed both to the cathode and to the anode. It is shown that the inversion of the direction of mass transfer of liquid through the bridge is due to the redistribution of volume charges. Keywords: water bridge, EHD flow, anode, cathode.

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9

Busic, Borislav, Joel Koplik, and Jayanth R. Banavar. "Molecular dynamics simulation of liquid bridge extensional flows." Journal of Non-Newtonian Fluid Mechanics 109, no. 1 (January 2003): 51–89. http://dx.doi.org/10.1016/s0377-0257(02)00163-5.

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10

THIESSEN, DAVID B., WEI WEI, and PHILIP L. MARSTON. "Active Electrostatic Control of Liquid Bridge Dynamics and Stability." Annals of the New York Academy of Sciences 1027, no. 1 (November 2004): 495–510. http://dx.doi.org/10.1196/annals.1324.039.

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11

Matsuoka, H., S. Fukui, and H. Morishita. "Dynamics of liquid meniscus bridge of intermittent contact slider." IEEE Transactions on Magnetics 38, no. 5 (September 2002): 2135–37. http://dx.doi.org/10.1109/tmag.2002.802692.

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12

UEKI, Yoshitaka, Hideaki MURASHIMA, and Masahiko SHIBAHARA. "Molecular Dynamics Study of Liquid Bridge Evaporation between Parallel Walls." Proceedings of Mechanical Engineering Congress, Japan 2018 (2018): J0530306. http://dx.doi.org/10.1299/jsmemecj.2018.j0530306.

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13

Wang, Long, Xiongying Li, Xuyan Zhou, Yifan Li, and Hui Li. "Drop formation and coalescence of liquid Au on nano carbon substrate." RSC Advances 6, no. 47 (2016): 41053–59. http://dx.doi.org/10.1039/c6ra04684c.

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14

Grohn, Philipp, Marius Lawall, Tobias Oesau, Stefan Heinrich, and Sergiy Antonyuk. "CFD-DEM Simulation of a Coating Process in a Fluidized Bed Rotor Granulator." Processes 8, no. 9 (September 2, 2020): 1090. http://dx.doi.org/10.3390/pr8091090.

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Coating of particles is a widely used technique in order to obtain the desired surface modification of the final product, e.g., specific color or taste. Especially in the pharmaceutical industry, rotor granulators are used to produce round, coated pellets. In this work, the coating process in a rotor granulator is investigated numerically using computational fluid dynamics (CFD) coupled with the discrete element method (DEM). The droplets are generated as a second particulate phase in DEM. A liquid bridge model is implemented in the DEM model to take the capillary and viscous forces during the wet contact of the particles into account. A coating model is developed, where the drying of the liquid layer on the particles, as well as the particle growth, is considered. The simulation results of the dry process compared to the simulations with liquid injection show an important influence of the liquid on the particle dynamics. The formation of liquid bridges and the viscous forces in the liquid layer lead to an increase of the average particle velocity and contact time. Changing the injection rate of water has an influence on the contact duration but no significant effect on the particle dynamics. In contrast, the aqueous binder solution has an important influence on the particle movement.

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15

TOKUMASU, Takashi, Nicolas FILLOT, and Philippe VERGNE. "J054014 Lubrication Phenomena of Nanoscale Liquid Bridge by Molecular Dynamics Method." Proceedings of Mechanical Engineering Congress, Japan 2011 (2011): _J054014–1—_J054014–4. http://dx.doi.org/10.1299/jsmemecj.2011._j054014-1.

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16

Gat, Amir, Homayun Navaz, and Morteza Gharib. "Dynamics of freely moving plates connected by a shallow liquid bridge." Physics of Fluids 23, no. 9 (September 2011): 097101. http://dx.doi.org/10.1063/1.3643289.

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17

Ponce-Torres, Alberto, Miguel A. Herrada, José M. Montanero, and José M. Vega. "Linear and nonlinear dynamics of an insoluble surfactant-laden liquid bridge." Physics of Fluids 28, no. 11 (November 2016): 112103. http://dx.doi.org/10.1063/1.4967289.

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18

Tokumasu, Takashi, Marie-Helene Meurisse, Nicolas Fillot, and Philippe Vergne. "A molecular dynamics study of a nanoscale liquid bridge under shear." Tribology International 59 (March 2013): 10–16. http://dx.doi.org/10.1016/j.triboint.2012.08.009.

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19

KOPLIK, JOEL, and JAYANTH R. BANAVAR. "MOLECULAR DYNAMICS SIMULATIONS OF NON-NEWTONIAN EXTENSIONAL FLUID FLOWS." International Journal of Modern Physics B 17, no. 01n02 (January 20, 2003): 27–32. http://dx.doi.org/10.1142/s0217979203017047.

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We discuss the use of molecular dynamics computer simulations in the extensional flow dynamics of polymeric, non-Newtonian liquids. The molecular model consists of Lennard-Jones monomers bound into linear chains by FENE potentials, a system known to exhibit characteristic non-Newtonian behavior such as shear thinning and normal stress differences. Here, we simulate liquid bridge flows in which cylinders of such liquids are placed between solid plates and extended to the point of rupture. Measurements of the local fluid stress tensor and interface shape provide information on extensional viscosity and rheology, coupled to microscopic information based on the evolution of molecular configurations. The simulations are in good agreement with laboratory data and with the results of macroscopic numerical calculations where available, but provide new and detailed information on the internal dynamics of liquids in extensional flow.

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20

Grohn, Philipp, Stefan Heinrich, and Sergiy Antonyuk. "Numerical Investigation of the Particle Dynamics in a Rotorgranulator Depending on the Properties of the Coating Liquid." Pharmaceutics 15, no. 2 (January 31, 2023): 469. http://dx.doi.org/10.3390/pharmaceutics15020469.

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In the pharmaceutical industry, the coating of particles is a widely used technique to obtain desired surface modifications of the final product, e.g., controlled release of the active agents. The production of round, coated particles is particularly important, which is why fluidized bed rotor granulators (FBRG) are often used for this process. In this work, Computational Fluid Dynamics (CFD) coupled with the Discrete Element Method (DEM) is used to investigate the wet particle dynamics, depending on the properties of the coating liquid in a FBRG. The DEM contact model was extended by liquid bridge model to account for capillary and viscous forces during wet contact of particles. The influence of the relative contact velocity on the maximum length of the liquid bridge is also considered in the model. Five different cases were compared, in which the particles were initially wetted, and the liquid loading as well as the surface tension and viscosity of the liquid were changed. The results show that increasing viscosity leads to a denser particle bed and a significant decrease in particle rotational velocities and particle motion in the poloidal plane of the FBRG. Reducing the liquid loading and surface tension results in increased particle movement.

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21

Jarrahbashi, D., W. A. Sirignano, P. P. Popov, and F. Hussain. "Early spray development at high gas density: hole, ligament and bridge formations." Journal of Fluid Mechanics 792 (March 1, 2016): 186–231. http://dx.doi.org/10.1017/jfm.2016.71.

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Three-dimensional temporal instabilities, leading to spray formation of a round liquid jet segment with an outer, coaxial high-density gas flow, are studied with Navier–Stokes and level-set computations. These computations predict the liquid surface shape showing the smaller structures on the conical wave crests, i.e. lobes, holes, bridges and ligaments, which are the precursors to droplet and spray formations. These structures and their time scales affect droplet size and velocity distributions as well as spray cone angles. The gas-to-liquid density ratio, liquid Reynolds number ($Re$) and liquid Weber number ($We$) range between 0.02–0.9, 320–16 000 and 2000–230 000, respectively, which cover three distinct physical domains. (1) At higher $Re$ and $We$, ligaments and then drops develop following hole and liquid bridge formations. (2) At higher gas densities throughout the $Re$ range, several holes merge forming two bridges per lobe before breaking to form ligaments; this hole merging is explained by slower development of hairpin vortices and lobe shape. (3) In cases where both gas density and $Re$ or $We$ are lower, the well-ordered lobes are replaced by more irregular, smaller-scale corrugations along the conical wave crest edge; ligaments form differently by stretching from the lobes before holes form. Thicker ligaments and larger droplets form in the low $Re$, low gas density range. The surface wave dynamics, vortex dynamics and their interactions are explained. Understandings of liquid stream break up and concurrent smaller structure formation are built upon an examination of both translation and rotation of the fluid. In all cases, hole formation is correlated with hairpin and helical vortices; fluid motion through a perforation in the thin sheet near the wave crest corresponds to these vortices. The hole formation process is dominated by inertial forces rather than capillary action, which differs from mechanisms suggested previously for other configurations. Circulation due to streamwise vorticity increases while the lobes thin and holes form. For larger surface tension, cavities in the jet core rather than perforations in a sheet occur. The more rapid radial extension of the two-phase mixture with increasing gas density is explained by greater circulation in the ring (i.e. wave crest) region. Experimental descriptions of the smaller structures are available only at lower $Re$ and lower density, agreeing with the computations. Computed scales of bridges, ligaments, early droplets and emerging spray radii agree qualitatively with experimental evidence through the high $Re$ and $We$ domains.

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22

Zhou, Nan, Jiayi Zhao, Shuo Chen, Yang Liu, and Kaixuan Zhang. "Simulation of liquid transfer between the plate and the groove." Modern Physics Letters B 34, no. 30 (July 25, 2020): 2050331. http://dx.doi.org/10.1142/s0217984920503315.

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The transfer of the liquid from groove to plate is significantly affected by the breakup process of liquid bridge, which is the core problem of gravure. In this paper, many-body dissipative particle dynamics method (MDPD) is used to simulate the behaviors of the stretching liquid cylinder between the plate and the groove, and the influence of surface wettability, stretching velocity and groove structure on the liquid cylinder rupture and the transfer rate of liquid are studied. The results show that both of the slipping velocity of the contact line on the plate and the thinning velocity of the liquid cylinder determine the breakup state of the liquid bridges and the liquid transfer rate from the groove to the plate. In the cases with the same surface wettability, at high hydrophilicity surface, the transfer rate increases firstly and then decreases with the increase of the stretching velocity. In the cases with different surface wettability of the plate and the groove, reducing the stretching velocity and the inclination angle of the groove are helpful to pull the liquid out of the groove and increase the transfer rate, and it could also be achieved by increasing the wettability of the plate and decreasing the wettability of the groove. This study provides some new insights into the effects of surface wettability, stretching velocity and groove structure on the dynamics of breakup process and liquid transfer in stretching.

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23

Шайхитдинов, Р. З., та Т. И. Шарипов. "Динамика массопереноса жидкости в водном мостике". Письма в журнал технической физики 48, № 11 (2022): 37. http://dx.doi.org/10.21883/pjtf.2022.11.52612.19161.

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The paper presents experimental results of the dynamics of mass transfer through a water bridge arising between two dielectric cups with distilled water under the action of a constant high-voltage voltage between cylindrical electrodes. It is established that, depending on the ratio of the electrode diameters, the total fluid flow in the water bridge can be directed both to the cathode and to the anode.It is shown that the inversion of the direction of mass transfer of liquid through the bridge is due to the redistribution of volume charges.

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24

Neeson, Michael J., Raymond R. Dagastine, Derek Y. C. Chan, and Rico F. Tabor. "Evaporation of a capillary bridge between a particle and a surface." Soft Matter 10, no. 42 (2014): 8489–99. http://dx.doi.org/10.1039/c4sm01826e.

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The liquid bridge that forms between a particle and a flat surface, and the dynamics of its evaporation are pertinent to a range of physical processes including paint and ink deposition, spray drying, evaporative lithography and the flow and processing of powders.

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25

Wei, Bo Sen, and Sang Woo Joo. "The Effect of Surface Wettability on Viscoelastic Droplet Dynamics under Electric Fields." Micromachines 13, no. 4 (April 7, 2022): 580. http://dx.doi.org/10.3390/mi13040580.

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The effects of surface wettability and viscoelasticity on the dynamics of liquid droplets under an electric field are studied experimentally. A needle-plate electrode system is used as the power source to polarize a dielectric plate by the corona discharge emitted at the needle electrode, creating a new type of steerable electric field realized. The dynamics of droplets between the dielectric plate and a conductive substrate include three different phenomena: equilibrium to a stationary shape on substrates with higher wettability, deformation to form a bridge between the top acrylic plate and take-off on the substrates with lower wettability. Viscoelastic droplets differ from water in the liquid bridge and takeoff phenomena in that thin liquid filaments appear in viscoelastic droplets, not observed for Newtonian droplets. The equilibrated droplet exhibits more pronounced heights for Newtonian droplets compared to viscoelastic droplets, with a decrease in height with the increase in the concentration of the elastic constituent in the aqueous solution. In the take-off phenomenon, the time required for the droplet to contact the upper plate decreases with the concentration of the elastic constituent increases. It is also found that the critical voltage required for the take-off phenomenon to occur decreases as the elasticity increases.

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26

Majumdar, Apala, Marchetti M. Cristina, and Epifanio G. Virga. "Perspectives in active liquid crystals." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, no. 2029 (November 28, 2014): 20130373. http://dx.doi.org/10.1098/rsta.2013.0373.

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Active soft matter is a young, growing field, with potential applications to a wide variety of systems. This Theme Issue explores this emerging new field by highlighting active liquid crystals. The collected contributions bridge theory to experiment, mathematical theories of passive and active nematics, spontaneous flows to defect dynamics, microscopic to continuum levels of description, spontaneous activity to biological activation. While the perspectives offered here only span a small part of this rapidly evolving field, we trust that they might provide the interested reader with a taste for this new class of non-equilibrium systems and their rich behaviour.

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27

Ye, Xijun, Zhuo Sun, Xu Cai, and Liu Mei. "An Improved Step-Type Liquid Level Sensing System for Bridge Structural Dynamic Deflection Monitoring." Sensors 19, no. 9 (May 9, 2019): 2155. http://dx.doi.org/10.3390/s19092155.

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Real-time and accurate monitoring of dynamic deflection is of great significance for health monitoring and condition assessment of bridge structures. This paper proposes an improved step-type liquid level sensing system (LLSS) for dynamic deflection monitoring. Layout of straight-line-type pipeline is replaced by step-type pipeline in this improved deflection monitoring system, which can remove the interference of the inclination angle on the measurement accuracy and is applicable for dynamic deflection monitoring. Fluid dynamics are first analyzed to demonstrate that measurement accuracy is interfered with by the fluid velocity induced by structural vibration, and ANSYS-FLOTRAN is applied for analyzing the influence range caused by the turbulent flow. Finally, a step-type LLSS model is designed and experimented with to verify the influence of the three key parameters (initial displacement excitation, step height, and distance from the measurement point to the elbow) on the measurement accuracy, and the reasonable placement scheme for the measurement point is determined. The results show that the measurement accuracy mainly depends on the turbulent flow caused by step height. The measurement error gets smaller after about 1.0 m distance from the elbow. To ensure that the measurement error is less than 6%, the distance between the measurement point and the elbow should be larger than 1.0 m.

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28

Hu, Renzhi, Manlelan Luo, Tongtong Liu, Lvjie Liang, Anguo Huang, Dmitry Trushnikov, K. P. Karunakaran, and Shengyong Pang. "Thermal fluid dynamics of liquid bridge transfer in laser wire deposition 3D printing." Science and Technology of Welding and Joining 24, no. 5 (March 29, 2019): 401–11. http://dx.doi.org/10.1080/13621718.2019.1591039.

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29

Li, W. L. "Dynamics of liquid meniscus bridge of a vibrating disk: consideration of flow rheology." Micro & Nano Letters 4, no. 1 (March 1, 2009): 44–47. http://dx.doi.org/10.1049/mnl:20090003.

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30

He, Yun Li, Hai Peng Liu, Shi Qiao Gao, and Cai Feng Wang. "Capillary Condensation Adhesion Phenomena and Analysis of the Micromechanical Gyroscope." Key Engineering Materials 562-565 (July 2013): 251–54. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.251.

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In MEMS, the size of micro-structure is usually in the micron and even nanoscale. It's easier to form capillary phenomenon than the macroscopic system. In view of this phenomenon, this article is based on the micro-mechanical gyroscope as the research object, to analyze the occurrence of capillary condensation of adhesion phenomenon. Firstly, we derive the Kelvin equation for capillary condensation, and then combination of the Kelvin equation introduce the capillary condensation of the adhesion phenomenon; Secondly, it analyzes the dynamics characteristics of its structure existing the liquid bridge, and analyzes the causes of the liquid bridge; Finally, it analyzes the capillary adhesion phenomena on the performance of the micro-mechanical gyroscope,as well as how to avoid the generation of capillary condensation adhesion.

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31

Gaponenko, Y., V. Yasnou, A. Mialdun, A. Nepomnyashchy, and V. Shevtsova. "Effect of the supporting disks shape on nonlinear flow dynamics in a liquid bridge." Physics of Fluids 33, no. 4 (April 2021): 042111. http://dx.doi.org/10.1063/5.0046379.

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32

Mo, Chao-jie, Li-zi Qin, and Li-jun Yang. "Crossover behavior study of a thinning liquid bridge using the dissipative particle dynamics method." Computers & Fluids 157 (November 2017): 232–39. http://dx.doi.org/10.1016/j.compfluid.2017.08.038.

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33

Wu, Mingqiu, Johannes G. Khinast, and Stefan Radl. "The effect of liquid bridge model details on the dynamics of wet fluidized beds." AIChE Journal 64, no. 2 (September 13, 2017): 437–56. http://dx.doi.org/10.1002/aic.15947.

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34

Beloborodov, Dmitry, and Aleksey Vishnyakov. "Molecular Dynamics of Nanodroplet Coalescence in Quasi-Saturated Vapor." Fluids 8, no. 2 (February 20, 2023): 77. http://dx.doi.org/10.3390/fluids8020077.

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The dynamics of coalescence of small Lennard–Jones droplets as a function of droplet size and temperature is explored with molecular simulations. Droplet sizes vary from several hundred to several thousand molecules, and three different temperatures are explored. As the droplets establish contact, a liquid-like bridge between them forms and grows, ultimately leading to a complete coalescence. The dynamics of the bridge growth are consistent with the “collective molecular jumps” mechanism reported in the literature rather than with the continuous interpretation of the coalescence process in terms of capillary and viscous forces. The effective coalescence time shows a linear growth with the droplet sizes. The influence of the larger droplet size is weaker but non-negligible. Surprisingly, practically no dependence of the coalescence time on the temperature is observed. Comparison of the coalescence times with the droplet lifespan in a suspension shows that for reasonably dense suspensions and small droplet sizes, the coalescence time becomes significant and should be accounted for in the theoretical models of aggregation.

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35

Charbonneau, Patrick, Yi Hu, Joyjit Kundu, and Peter K. Morse. "The dimensional evolution of structure and dynamics in hard sphere liquids." Journal of Chemical Physics 156, no. 13 (April 7, 2022): 134502. http://dx.doi.org/10.1063/5.0080805.

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The formulation of the mean-field infinite-dimensional solution of hard sphere glasses is a significant milestone for theoretical physics. How relevant this description might be for understanding low-dimensional glass-forming liquids, however, remains unclear. These liquids indeed exhibit a complex interplay between structure and dynamics, and the importance of this interplay might only slowly diminish as dimension d increases. A careful numerical assessment of the matter has long been hindered by the exponential increase in computational costs with d. By revisiting a once common simulation technique involving the use of periodic boundary conditions modeled on D d lattices, we here partly sidestep this difficulty, thus allowing the study of hard sphere liquids up to d = 13. Parallel efforts by Mangeat and Zamponi [Phys. Rev. E 93, 012609 (2016)] have expanded the mean-field description of glasses to finite d by leveraging the standard liquid–state theory and, thus, help bridge the gap from the other direction. The relatively smooth evolution of both the structure and dynamics across the d gap allows us to relate the two approaches and to identify some of the missing features that a finite- d theory of glasses might hope to include to achieve near quantitative agreement.

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36

Kikkinides, E. S., G. Gkogkos, P. A. Monson, and R. Valiullin. "Connecting dynamic pore filling mechanisms with equilibrium and out of equilibrium configurations of fluids in nanopores." Journal of Chemical Physics 156, no. 13 (April 7, 2022): 134702. http://dx.doi.org/10.1063/5.0087249.

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In the present study, using dynamic mean field theory complemented by grand canonical molecular dynamics simulations, we investigate the extent to which the density distributions encountered during the dynamics of capillary condensation are related to those distributions at equilibrium or metastable equilibrium in a system at fixed average density (canonical ensemble). We find that the states encountered can be categorized as out of equilibrium or quasi-equilibrium based on the magnitude of the driving force for mass transfer. More specifically, in open-ended slit pores, pore filling via double bridging is an out of equilibrium process, induced by the dynamics of the system, while pore filling by single bridge formation is connected to a series of configurations that are equilibrium configurations in the canonical ensemble and that cannot be observed experimentally by a standard adsorption process, corresponding to the grand canonical ensemble. Likewise, in closed cap slits, the formation of a liquid bridge near the pore opening and its subsequent growth while the initially detached meniscus from the capped end remains immobilized are out of equilibrium processes that occur at large driving forces. On the other hand, at small driving forces, there is a continuous acceleration of the detached meniscus from the capped end, which is associated with complete reversibility in the limit of an infinitesimally small driving force.

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37

Sprittles, James E., and Yulii D. Shikhmurzaev. "The coalescence of liquid drops in a viscous fluid: interface formation model." Journal of Fluid Mechanics 751 (June 24, 2014): 480–99. http://dx.doi.org/10.1017/jfm.2014.313.

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AbstractThe interface formation model is applied to describe the initial stages of the coalescence of two liquid drops in the presence of a viscous ambient fluid whose dynamics is fully accounted for. Our focus is on understanding (a) how this model’s predictions differ from those of the conventionally used one, (b) what influence the ambient fluid has on the evolution of the shape of the coalescing drops and (c) the coupling of the intrinsic dynamics of coalescence and that of the ambient fluid. The key feature of the interface formation model in its application to the coalescence phenomenon is that it removes the singularity inherent in the conventional model at the onset of coalescence and describes the part of the free surface ‘trapped’ between the coalescing volumes as they are pressed against each other as a rapidly disappearing ‘internal interface’. Considering the simplest possible formulation of this model, we find experimentally verifiable differences with the predictions of the conventional model showing, in particular, the effect of drop size on the coalescence process. According to the new model, for small drops a non-monotonic time dependence of the bridge expansion speed is a feature that could be looked for in further experimental studies. Finally, the results of both models are compared to recently available experimental data on the evolution of the liquid bridge connecting coalescing drops, and the interface formation model is seen to give a better agreement with the data.

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38

Trittel, Torsten, Christoph Klopp, Kirsten Harth, and Ralf Stannarius. "Stability and Rupture of Liquid Crystal Bridges under Microgravity." Crystals 12, no. 8 (August 4, 2022): 1092. http://dx.doi.org/10.3390/cryst12081092.

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Liquid-crystal columns were prepared and observed under microgravity aboard suborbital TEXUS rocket flights. The microgravity phase of each flight lasted for approximately six minutes. We tested structures in different liquid-crystalline mesophases. In the isotropic and nematic phases, the Rayleigh-Plateau instability led to the collapse of the columns. However, in the smectic A and C mesophases, it was found that the columns survived the extension to slenderness ratios (length/diameter) of over 4.5 (and in one case, more than 6). The liquid-crystalline material in the millimeter-sized columns was macroscopically disordered. Thus, regular shell-like internal layer structures that stabilized the columns can be excluded. Instead, the reason for their persistence was the yield stress of the material, which is quite different for the different mesophases. In the columnar mesophase, the cylindrical bridge even survived the strong deceleration when the rocket re-entered the atmosphere. During the breakup of the filaments, the neck thinning dynamics were determined.

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39

Tokumasu, Takashi, Marie-Helene Meurisse, Nicolas Fillot, and Philippe Vergne. "OS6-1-2 A Molecular Dynamics Study for the Transport Phenomena of a Nanoscale Liquid Bridge." Proceedings of the Symposium on Micro-Nano Science and Technology 2012.4 (2012): 133–34. http://dx.doi.org/10.1299/jsmemnm.2012.4.133.

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40

Ng, Henry, Mediha Becirovic Agic, Michael Hultström, and Henrik Isackson. "Optimal cutting temperature medium embedding and cryostat sectioning are valid for cardiac myofilament function assessment." American Journal of Physiology-Heart and Circulatory Physiology 319, no. 1 (July 1, 2020): H235—H241. http://dx.doi.org/10.1152/ajpheart.00194.2020.

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Myocardial tissue in optimal cutting temperature (OCT) fixation and cryostat sectioning was tested as a means of storing and preparing tissue for myofilament function analysis in relation to conventional liquid nitrogen freezing and dissection. Actomyosin interaction, Ca2+ force activation, and passive compliance were tested. The study concluded that OCT storage and cryostat sectioning do not interfere with the actomyosin cross-bridge dynamics or Ca2+ activation but that absolute tension values suffer and may not be investigated by this method.

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41

Pocheć, Michał, Katarzyna M. Krupka, Jarosław J. Panek, Kazimierz Orzechowski, and Aneta Jezierska. "Inside out Approach to Rotator State in Hydrogen-Bonded System—Experimental and Theoretical Cross-Examination in n-Octanol." International Journal of Molecular Sciences 23, no. 4 (February 15, 2022): 2138. http://dx.doi.org/10.3390/ijms23042138.

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The experimental and theoretical description of premelting behavior is one of the most challenging tasks in contemporary material science. In this paper, n-octanol was studied using a multi-method approach to investigate it at macroscopic and molecular levels. The experimental infrared (IR) spectra were collected in the solid state and liquid phase at temperature range from −84∘C to −15 ∘C to detect temperature-related indicators of pretransitional phenomena. Next, the nonlinear dielectric effect (NDE) was measured at various temperatures (from −30 ∘C to −15 ∘C) to provide insight into macroscopic effects of premelting. As a result, a two-step mechanism of premelting in n-octanol was established based on experimental data. It was postulated that it consists of a rotator state formation followed by the surface premelting. In order to shed light onto molecular-level processes, classical molecular dynamics (MD) was performed to investigate the time evolution of the changes in metric parameters as a function of simulation temperature. The applied protocol enabled simulations in the solid state as well as in the liquid (the collapse of the ordered crystal structure). The exact molecular motions contributing to the rotator state formation were obtained, revealing an enabling of the rotational freedom of the terminal parts of the chains. The Car–Parrinello molecular dynamics (CPMD) was applied to support and interpret experimental spectroscopic findings. The vibrational properties of the stretching of OH within the intermolecular hydrogen bond were studied using Fourier transformation of the autocorrelation function of both dipole moments and atomic velocity. Finally, path integral molecular dynamics (PIMD) was carried out to analyze the quantum effect’s influence on the bridged proton position in the hydrogen bridge. On the basis of the combined experimental and theoretical conclusions, a novel mechanism of the bridged protons dynamics has been postulated—the interlamellar hydrogen bonding pattern, resulting in an additional OH stretching band, visible in the solid-state experimental IR spectra.

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42

Heinen, Matthias, Marco Hoffmann, Felix Diewald, Steffen Seckler, Kai Langenbach, and Jadran Vrabec. "Droplet coalescence by molecular dynamics and phase-field modeling." Physics of Fluids 34, no. 4 (April 2022): 042006. http://dx.doi.org/10.1063/5.0086131.

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Coalescence of argon droplets with a radius of 25, 50, and 100 nm is studied with computational methods. Molecular dynamics (MD) simulations are carried out to generate reference data. Moreover, a phase-field model resting on a Helmholtz energy equation of state is devised and evaluated by computational fluid dynamics (CFD) simulations. Exactly the same scenarios in terms of geometry, fluid, and state are considered with these approaches. The MD and CFD simulation results show an excellent agreement over the entire coalescence process, including the decay of the inertia-induced oscillation of the merged droplet. Theoretical knowledge about the asymptotic behavior of coalescence process regimes is confirmed. All considered scenarios cross from the inertially limited viscous regime over to the inertial regime because of the low shear viscosity of argon. The particularly rapid dynamics during the initial stages of the coalescence process in the thermal regime is also captured by the phase-field model, where a closer look at the liquid density reveals that metastable states associated with negative pressure are attained in the emerging liquid bridge between the coalescing droplets. This demonstrates that this model is even capable of adequately handling the onset of coalescence. To speed up CFD simulations, the phase-field model is transferred to coarser grids through an interface widening approach that retains the thermodynamic properties including the surface tension.

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43

Kim, Yong-Jae, Yun-Hee Lee, Sooheyong Lee, Hiroki Nada, and Geun Woo Lee. "Shock growth of ice crystal near equilibrium melting pressure under dynamic compression." Proceedings of the National Academy of Sciences 116, no. 18 (April 15, 2019): 8679–84. http://dx.doi.org/10.1073/pnas.1818122116.

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Crystal growth is governed by an interplay between macroscopic driving force and microscopic interface kinetics at the crystal–liquid interface. Unlike the local equilibrium growth condition, the interplay becomes blurred under local nonequilibrium, which raises many questions about the nature of diverse crystal growth and morphological transitions. Here, we systematically control the growth condition from local equilibrium to local nonequilibrium by using an advanced dynamic diamond anvil cell (dDAC) and generate anomalously fast growth of ice VI phase with a morphological transition from three- to two-dimension (3D to 2D), which is called a shock crystal growth. Unlike expected, the shock growth occurs from the edges of 3D crystal along the (112) crystal plane rather than its corners, which implies that the fast compression yields effectively large overpressure at the crystal–liquid interface, manifesting the local nonequilibrium condition. Molecular dynamics (MD) simulation reproduces the faster growth of the (112) plane than other planes upon applying large overpressure. Moreover, the MD study reveals that the 2D shock crystal growth originates from the similarity of the interface structure between water and the (112) crystal plane under the large overpressure. This study provides insight into crystal growth under dynamic compressions, which makes a bridge for the unknown behaviors of crystal growth between under static and dynamic pressure conditions.

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44

Kostoglou, M., and T. D. Karapantsios. "Analysis of bubble-in-liquid bridge configuration as prototype for studying foam dynamics. Zero Bond number case." Colloids and Surfaces A: Physicochemical and Engineering Aspects 460 (October 2014): 386–90. http://dx.doi.org/10.1016/j.colsurfa.2013.12.045.

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45

Campana, Diego M., and Marcio S. Carvalho. "Liquid transfer from single cavities to rotating rolls." Journal of Fluid Mechanics 747 (April 23, 2014): 545–71. http://dx.doi.org/10.1017/jfm.2014.175.

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AbstractIn this work we study computationally the dynamics of a liquid bridge formed between a two-dimensional trapezoidal cavity, which represents an axisymmetric cell or a plane groove engraved in a roll, and a moving plate. The flow is a model of the liquid transfer process in gravure printing systems. The considered plate kinematics represents the actual motion of a roll-to-roll system, which includes extension, shear and rotation relative to the cavity. The fluid flow is modelled by solving the Stokes equations, discretized with the finite element method; the evolving free surfaces are accommodated by employing a pseudosolid mesh deforming algorithm. The results show that as the roll radius is reduced, thus increasing the lateral and rotational motions of the top plate relative to the cavity, a larger volume of liquid is transferred to the plate. However, due to lateral displacement of the contact lines, special care must be taken concerning the wettability properties of the substrate to avoid errors in the pattern fidelity. The predictions also show a strong nonlinear behaviour of the liquid fraction extracted from a cavity as a function of the capillary number. At high capillary numbers the fluid dynamics is mainly controlled by the extensional motion due to the strong contact line pinning. However, at low values of the capillary number, the contact lines have higher mobility and the liquid fraction primarily depends on the lateral and rotational plate velocity. These mechanisms tend to drag the fluid outside the cavity and increase the liquid fraction transferred to the plate, as has been observed in experiments.

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46

Arabzade, Amir, Nic Laboe, Siri Ippagunta, Eric Emanus, Alisha Kardian, and Stephen Mack. "EPEN-03. ZFTA-RELA LOCALIZATION DYNAMICS REGULATE TRANSCRIPTIONAL CONTROL." Neuro-Oncology 25, Supplement_1 (June 1, 2023): i27. http://dx.doi.org/10.1093/neuonc/noad073.107.

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Abstract ZFTA gene fusions are the most frequent driver events in supratentorial ependymoma (EPN). ZFTA-fusion proteins act as oncogenic transcription factors (TFs) to aberrantly activate oncogenic transcriptional programs. Our data indicates that ZFTA fusion proteins form distinct punctate structures with heterogeneous patterns of liquid-phase-like characteristics. These condensates are closely associated with transcription as seen by nascent RNA FISH and recruitment of various members of the transcription machinery, such as BRD4, MED1, and RNA POLII. Our genomic footprinting data indicates that many key transcription factors, such as Sox9, share similar genomic occupancy patterns with ZFTA fusions suggesting that these transcription factors are potentially recruited to these condensates, establishing transcriptional hubs. Our mutagenesis studies reveal that the ZFTA zinc finger domain is indispensable for condensate formation, and may bridge ZFTA fusion proteins to DNA at unique genomic loci. Condensate-forming deficient mutants fail to establish the same transcriptional program and are unable to drive tumor formation. This mechanistic data has led to our efforts to establish drug-chemical screen approaches against ZFTA-RELA localization/dynamics to identify novel therapeutic targets.

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47

Yaneva, Jacqueline, Andrey Milchev, and Kurt Binder. "Polymer droplets on substrates with striped surface domains: molecular dynamics simulations of equilibrium structure and liquid bridge rupture." Journal of Physics: Condensed Matter 17, no. 49 (November 25, 2005): S4199—S4211. http://dx.doi.org/10.1088/0953-8984/17/49/014.

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48

Chen, Hao, Xiaolong Pan, Qichun Nie, Qianli Ma, Haisheng Fang, and Zhouping Yin. "Probing the coalescence of non-Newtonian droplets on a substrate." Physics of Fluids 34, no. 3 (March 2022): 032109. http://dx.doi.org/10.1063/5.0085765.

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To better understand the coalescence of droplets, which play critical roles in diverse natural processes and industrial applications, we give attention to the non-Newtonian rheology of liquid drops—in particular, studying the coalescence of two non-Newtonian droplets on a solid surface, with special attention to the effect of the shear thinning behavior. Based on a theoretical power-law model, we show that the height [Formula: see text] of the liquid bridge connecting two adjacent droplets grows with a power function of time as [Formula: see text], where [Formula: see text] indicates the power-law exponent. Through numerical simulations, we reveal a self-similar regime during the initial stage of coalescence and propose an accurate prediction for capturing the spatial structure of the flow. Our results also update the effect of the contact angle, which significantly alters the coalescence dynamics.

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49

Nagy, Tamás Milán, Krisztina Knapp, Eszter Illyés, István Timári, Gitta Schlosser, Gabriella Csík, Attila Borics, Zsuzsa Majer, and Katalin E. Kövér. "Photochemical and Structural Studies on Cyclic Peptide Models." Molecules 23, no. 9 (August 30, 2018): 2196. http://dx.doi.org/10.3390/molecules23092196.

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Ultra-violet (UV) irradiation has a significant impact on the structure and function of proteins that is supposed to be in relationship with the tryptophan-mediated photolysis of disulfide bonds. To investigate the correlation between the photoexcitation of Trp residues in polypeptides and the associated reduction of disulfide bridges, a series of small, cyclic oligopeptide models were analyzed in this work. Average distances between the aromatic side chains and the disulfide bridge were determined following molecular mechanics (MM) geometry optimizations. In this way, the possibility of cation–π interactions was also investigated. Molecular mechanics calculations revealed that the shortest distance between the side chain of the Trp residues and the disulfide bridge is approximately 5 Å in the cyclic pentapeptide models. Based on this, three tryptophan-containing cyclopeptide models were synthesized and analyzed by nuclear magnetic resonance (NMR) spectroscopy. Experimental data and detailed molecular dynamics (MD) simulations were in good agreement with MM geometry calculations. Selected model peptides were subjected to photolytic degradation to study the correlation of structural features and the photolytic cleavage of disulfide bonds in solution. Formation of free sulfhydryl groups upon illumination with near UV light was monitored by fluorescence spectroscopy after chemical derivatization with 7-diethylamino-3-(4-maleimidophenyl)-4-methylcoumarin (CPM) and mass spectrometry. Liquid cromatography-mass spectrometry (LC-MS) measurements indicated the presence of multiple photooxidation products (e.g., dimers, multimers and other oxidated products), suggesting that besides the photolysis of disulfide bonds secondary photolytic processes take place.

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50

Kang, Botao, Pengcheng Liu, Chenxi Li, Yiyi Sun, Peng Xiao, and Jiawei Tang. "A Prediction Method for Flow-Stop Time in Deep-Water Volatile Oilfields: A Case Study of Akpo Oilfield in Niger Delta Basin." Geofluids 2021 (July 14, 2021): 1–14. http://dx.doi.org/10.1155/2021/2941565.

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Due to the difference in oil and water density, the wellhead pressure continues to decrease with water-cut rising in deep-water volatile oilfields. Once it is close to the lower limit, the production well will stop flowing. This phenomenon seriously affects the production and recoverable reserves. By taking the dynamic relative permeability which can reflect the macroscopic movement of oil and water in the reservoir as an intermediate bridge, production performance has been combined with dominant reservoir factors, including reservoir structure, reservoir connectivity, and heterogeneity. By the statistical analysis of actual data, this paper clarified the quantitative relationships between dominant reservoir factors and production performance and established the refined prediction methods for production dynamics including water-cut and liquid production rate. A prediction method for the wellhead pressure was further established, and the flow-stop time of single well can be accurately predicted. The results can be used in annual production forecast and recoverable reserve evaluation. This method had been successfully applied in Akpo oilfields in the Niger Basin. The results show that the production dynamics are significantly affected by reservoir factors in deep-water turbidite sandstone reservoir and the prediction method considering reservoir factors will be much more applicable. In deep-water volatile oilfields, the flow-stop risk of the production well in middle and high water-cut stages is very great and is mainly affected by the water-cut and liquid production rate. Judging from the application effect of Akpo oilfields, this method has high prediction accuracy and can be used to guide optimization and adjustment in deep-water oilfields.

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