scholarly journals Simulation of Shear-Thickening Liquid Transfer between U-Shaped Cell and Flat Plate

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 838
Author(s):  
Ling Dong ◽  
Jiefang Xing ◽  
Shuang Wu ◽  
Xiaomin Guan ◽  
Hongjuan Zhu
Keyword(s):  
Contact Angle ◽  
Transfer Rate ◽  
Substrate Surface ◽  
Shear Thickening ◽  
Cell Contact ◽  
Moving Plate ◽  
Printing Plate ◽  
Actual Measurement ◽  
Shaped Cell ◽  
Liquid Transfer

Based on the actual measurement of the shear-thickening properties of water-based inks, in order to improve the ink transfer rate, the PLIC (Piecewise Linear Interface Construction) interface tracking method and the VOF (Volume of Fluid) method are used to simulate the transfer process of the shear-thickening liquid between the U-shaped cell and the upwardly moving plate. The effects of substrate surface wettability, cell contact angle, and cell depth on liquid transfer were studied. The results showed that all can increase the liquid transfer rate, and the change of the cell contact angle also led to the difference in the breaking time of the liquid filament. In addition, the shallow plate effect was discovered in the study of cell depth. The shallow plate effect is a phenomenon by which the amount of liquid transferred and the liquid transfer rate are greatly improved when the depth of the cell decreases to a certain limit value. In addition, for the U-shaped cell, the optimization method combining the shallow printing plate effect and fillet can greatly improve the liquid transfer rate and solve the undesirable problems such as plate blocking. After optimization, a liquid transfer rate of about 85% can be achieved.

Simulation of liquid transfer between the plate and the groove

2020 ◽  
Vol 34 (30) ◽  
pp. 2050331
Author(s):  
Nan Zhou ◽  
Jiayi Zhao ◽  
Shuo Chen ◽  
Yang Liu ◽  
Kaixuan Zhang
Keyword(s):  
Transfer Rate ◽  
Dissipative Particle Dynamics ◽  
Surface Wettability ◽  
Breakup Process ◽  
Many Body ◽  
The Core ◽  
Groove Structure ◽  
Liquid Transfer ◽  
Core Problem ◽  
Dynamics Method

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.

scholarly journals Prediction of Contact Angle of Nanofluids by Single-Phase Approaches

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4558 ◽  
Author(s):  
Nur Çobanoğlu ◽  
Ziya Haktan Karadeniz ◽  
Patrice Estellé ◽  
Raul Martínez-Cuenca ◽  
Matthias H. Buschmann
Keyword(s):  
Contact Angle ◽  
Single Phase ◽  
Substrate Surface ◽  
Droplet Surface ◽  
Force Balance ◽  
Radius Of Curvature ◽  
Geometrical Parameters ◽  
Ambient Conditions ◽  
Sessile Droplet ◽  
Droplet Shape

Wettability is the ability of the liquid to contact with the solid surface at the surrounding fluid and its degree is defined by contact angle (CA), which is calculated with balance between adhesive and cohesive forces on droplet surface. Thermophysical properties of the droplet, the forces acting on the droplet, atmosphere surrounding the droplet and the substrate surface are the main parameters affecting on CA. With nanofluids (NF), nanoparticle concentration and size and shape can modify the contact angle and thus wettability. This study investigates the validity of single-phase CA correlations for several nanofluids with different types of nanoparticles dispersed in water. Geometrical parameters of sessile droplet (height of the droplet, wetting radius and radius of curvature at the apex) are used in the tested correlations, which are based on force balance acting on the droplet surface, energy balance, spherical dome approach and empirical expression, respectively. It is shown that single-phase models can be expressed in terms of Bond number, the non-dimensional droplet volume and two geometrical similarity simplexes. It is demonstrated that they can be used successfully to predict CA of dilute nanofluids’ at ambient conditions. Besides evaluation of CA, droplet shape is also well predicted for all nanofluid samples with ±5% error.

scholarly journals Deformation of an elastic substrate due to a resting sessile droplet

2017 ◽  
Vol 29 (2) ◽  
pp. 281-300 ◽  
Author(s):  
AARON BARDALL ◽  
KAREN E. DANIELS ◽  
MICHAEL SHEARER
Keyword(s):  
Contact Angle ◽  
Contact Line ◽  
Substrate Surface ◽  
Fluid Pressure ◽  
Force Balance ◽  
Energy Conditions ◽  
Equilibrium Contact Angle ◽  
Solution Technique ◽  
Vertical Force ◽  
Tangential Contact

On a sufficiently soft substrate, a resting fluid droplet will cause significant deformation of the substrate. This deformation is driven by a combination of capillary forces at the contact line and the fluid pressure at the solid surface. These forces are balanced at the surface by the solid traction stress induced by the substrate deformation. Young's Law, which predicts the equilibrium contact angle of the droplet, also indicates an a priori radial force balance for rigid substrates, but not necessarily for soft substrates that deform under loading. It remains an open question whether the contact line transmits a non-zero force tangent to the substrate surface in addition to the conventional normal (vertical) force. We present an analytic Fourier transform solution technique that includes general interfacial energy conditions, which govern the contact angle of a 2D droplet. This includes evaluating the effect of gravity on the droplet shape in order to determine the correct fluid pressure at the substrate surface for larger droplets. Importantly, we find that in order to avoid a strain singularity at the contact line under a non-zero tangential contact line force, it is necessary to include a previously neglected horizontal traction boundary condition. To quantify the effects of the contact line and identify key quantities that will be experimentally accessible for testing the model, we evaluate solutions for the substrate surface displacement field as a function of Poisson's ratio and zero/non-zero tangential contact line forces.

scholarly journals Pressure effect during the formation of a selective layer on the structure and performance of dynamic composite membranes for pervaporation

2021 ◽  
Vol 65 (4) ◽  
pp. 431-438
Author(s):  
K. S. Burts ◽  
T. V. Plisko ◽  
A. V. Bildyukevich ◽  
G. Li ◽  
J. Kujawa ◽  
...  
Keyword(s):  
Contact Angle ◽  
Polymer Matrix ◽  
Composite Membrane ◽  
Substrate Surface ◽  
Composite Membranes ◽  
Feed Solution ◽  
Porous Membrane ◽  
Transmembrane Pressure ◽  
Dynamic Mode ◽  
Selective Layer

Composite membranes for pervaporation were prepared by forming a selective layer based on cross-linked polyvinyl alcohol (PVA) on the porous membrane-substrate surface in the dynamic mode (via PVA solution ultrafiltration). It was found that the pressure growth results in increasing the thickness of the composite membrane selective layer. Composite membrane contact angle, flux, water content in permeate in ethanol/water (mass ratio 90/10) pervaporation were revealed to have maximum values at 3–4 atm depending on the PVA concentration in the feed solution. It was shown that the revealed dependence of the contact angle, selectivity, and permeability on the pressure of the selective layer formation is due to the compaction of the polymer matrix-substrate under the action of the transmembrane pressure and its relaxation after pressure release. When using elevated pressures (more than 3–4 atm), the relaxation of the polymer matrix causes the microdefect to form as a result of deformation of the selective layer.

Numerical Studies of Stretching Liquid Bridges Between Two Spherical Solid Particles With Different Contact Angles

2010 ◽  
Author(s):  
Pirooz Darabi ◽  
Konstantin Pougatch ◽  
Martha Salcudean ◽  
Dana Grecov
Keyword(s):  
Contact Angle ◽  
Capillary Number ◽  
Contact Angles ◽  
Solid Particles ◽  
Spherical Particles ◽  
Liquid Bridges ◽  
Liquid Distribution ◽  
Liquid Transfer ◽  
Static Conditions ◽  
Rupture Distance

Numerical simulations of the governing Navier-Stokes equations are used to predict the rupture and liquid distribution of stretching liquid bridges between two equal-sized solid spherical particles with different liquid-solid contact angles. A commercial computational fluid dynamics (CFD) tool — FLUENT — is used. The effects of the capillary number and contact angle on the rupture distance and liquid transfer fraction are studied. The simulation results show that for particles with different contact angles, the rupture distance increases as the capillary number is increased; this is similar to the case of particles with identical contact angles. Also, it is shown that for quasi-static conditions, the rupture distance decreases as the difference between the contact angles is increased. Plots of the variations of the liquid transfer fraction with respect to the capillary number show three zones: (1) for high capillary numbers, liquid is almost equally distributed (dynamic zone); (2) for low capillary numbers, the liquid transfer fraction depends on the contact angles and more liquid is transferred to the particle with the smaller contact angle (quasi-static zone); (3) at intermediate capillary numbers, the curve connecting the above limiting conditions resembles an S-shape (transition zone), showing the dependency of the liquid distribution on both capillary number and contact angles. The trends are consistent with the experimental findings published in the literature.

Study of Super Hydrophobic Films on Pre-Sensitized Plate Aluminium Substrate

2012 ◽  
Vol 200 ◽  
pp. 427-429
Author(s):  
Zhuang Liu ◽  
Lin Zhu ◽  
Jing Lin ◽  
Zhi Hui Sun
Keyword(s):  
Contact Angle ◽  
Rough Surface ◽  
Chemical Etching ◽  
Substrate Surface ◽  
Acid Etching ◽  
Etching Time ◽  
Hydrophobic Property ◽  
Aluminium Substrate ◽  
Simple Chemical ◽  
Etched Surface

A simple chemical etching method was developed for corrosion of the pre-sensitized plate aluminium substrate in order to be a rough surface. After the chemical etched surface was treated with fluorination, the pre-sensitized (PS) plate aluminium (Al) substrate surface exhibits a super-hydrophobic property. The effects of the etching time and the etchant concentration on the super-hydrophobici were investigated, and the results show the contact angle of hydrofluoric firstly increases then reduce with acid etching time increasing, and the optimum etching time is 12 min; the contact angle of hydrofluoric firstly increases then reduce with acid etchant concentration increasing, and the optimum etchant concentration is 3 mol /L. When the contact angle increases, the droplet and solid surface tension increases. Film base fine structure of the rough surface is the key to the formation of hydrophobic.

The effect of shear-thickening on liquid transfer from an idealized gravure cell

2015 ◽  
Vol 221 ◽  
pp. 55-65 ◽  
Author(s):  
Sunilkumar Khandavalli ◽  
J. Alex Lee ◽  
Matteo Pasquali ◽  
Jonathan P. Rothstein
Keyword(s):  
Shear Thickening ◽  
Liquid Transfer

scholarly journals Analysis of Arrhenius Kinetics on Multiphase Flow between a Pair of Rotating Circular Plates

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
M. B. Arain ◽  
M. M. Bhatti ◽  
A. Zeeshan ◽  
Tareq Saeed ◽  
Aatef Hobiny
Keyword(s):  
Flow Behavior ◽  
Fluid Velocity ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Three Dimensions ◽  
Fluid Viscosity ◽  
Circular Plates ◽  
Carreau Fluid ◽  
Moving Plate ◽  
The Impact

In this study, we aim to deal with the flow behavior betwixt a pair of rotating circular plates filled with Carreau fluid under the suspension of nanoparticles and motile gyrotactic microorganisms in the presence of generalized magnetic Reynolds number. The activation energy is also contemplated with the nanoparticle concentration equation. The appropriate similarity transformations are used to formulate the proposed mathematical modeling in the three dimensions. The outcomes of the torque on both plates, i.e., the fix and the moving plate, are also contemplated. A well-known differential transform method (DTM) with a combination of Padé approximation will be implemented to get solutions to the coupled nonlinear ordinary differential equations (ODEs). The impact of different nondimensional physical aspects on velocity profile, temperature, concentration, and motile gyrotactic microorganism functions is discussed. The shear-thinning fluid viscosity decreases with shear strain due to its high velocity compared to the Newtonian and shear-thickening case. The impact of Carreau fluid velocity for shear-thinning n < 1 , Newtonian case n = 0 , and shear-thickening n > 1 cases on axial velocity distribution f ′ λ has been discussed in tabular form and graphical figures. For the validation of the current methodology, a comparison is made between DTM-Padé and the numerical shooting scheme.

Measurement System of Contact Angle between Molten Steel Droplet and Refractory Material

2011 ◽  
Vol 299-300 ◽  
pp. 277-281
Author(s):  
Xiao Lin Qiu ◽  
Guo Wei Chang ◽  
Shu Ying Chen ◽  
Jian Guo He
Keyword(s):  
Contact Angle ◽  
Refractory Material ◽  
Molten Steel ◽  
Measurement System ◽  
Mean Deviation ◽  
Maximum Deviation ◽  
Actual Measurement ◽  
C Language ◽  
Computer Image Processing ◽  
Measurement Results

The distinct images of molten steel droplets were obtained utilizing a home-made experimental equipment, and the method which measures the contact angle between the molten steel droplet and the refractory material using a computer image processing technology and Visual C++ language was represented, meanwhile the measurement system of the contact angle was developed. The results show that the maximum deviation of the measurement system is 0.13° comparing with the actual measurement results, the minimum deviation is 0.03°, and the mean deviation is 0.06°. Under this experiment conditions, the contact angle increases 1.2° when the quality of sample increases from 0.2g to 0.8g at 1550°C, and the contact angle increases 2.3° when the temperature increases from 1550°C to 1600°C for the sample of 0.2g.

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