A numerical approach for the direct computation of flows including fluid-solid interaction: Modeling contact angle, film rupture, and dewetting

2016 ◽  
Vol 28 (6) ◽  
pp. 062002 ◽  
Author(s):  
K. Mahady ◽  
S. Afkhami ◽  
L. Kondic
2018 ◽  
Vol 419 ◽  
pp. 268-280 ◽  
Author(s):  
I. Zenzerovic ◽  
W. Kropp ◽  
A. Pieringer

Author(s):  
Liang-Yee Cheng ◽  
Diogo Vieira Gomes ◽  
Adriano Mitsuo Yoshino ◽  
Kazuo Nishimoto

The objective of the present paper is to carry out numerical simulations on the coupled transient processes of oil leakage, water flooding and study of the stability in a damaged crude oil carrier. For this purpose, numerical approach based on Moving Particle Semi-Implicit (MPS) method is applied to model the complex fluid-solid interaction problem with free surface and oil-water multiphase flow. Changes on the modeling of the towing tank utilized in a previous study on oil leakage carried by the author are done to reduce the undesirable effects of the wave reflection. As a consequence, the improved results of the transient behaviors of hull motions are obtained for the cases with oil leak, as well as the final list angle and volume inside the tank in cases of water flooding. The results of the simulations show that the volume of flooded water is inversely proportional to the filling ratio. Also, the height of the opening has not significant effect on the final list and flooded volume.


Soft Matter ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 587-599 ◽  
Author(s):  
Jueying Wu ◽  
Iliana Delcheva ◽  
Yung Ngothai ◽  
Marta Krasowska ◽  
David A. Beattie

Bubble rise and collision against a graphite surface pre-treated with an adsorbed layer of carboxymethylcellulose. The adsorbed layer can prolong wetting film rupture, dramatically slow the dewetting of the mineral surface, and reduce the final contact angle of the bubble. Adsorption of CMC from a solution of higher polymer concentration amplifies the effect of the polymer.


Author(s):  
Nastaran Hashemi ◽  
Mark Paul ◽  
Javier Alcazar ◽  
Raul Radovitzky

Many micro and nano-technologies rely upon the complicated motion of objects immersed in a viscous fluid. It is often the case that for such problems analytical theory is not available to quantitatively describe and predict the device dynamics. In addition, the numerical simulation of such devices involves moving boundaries and use of the standard Eulerian computational approaches are often difficult to implement. In order to address this problem we use and validate a fully Lagrangian finite element approach that treats the moving boundaries in a natural manner. We validate the method for use in calculating the dynamics of oscillating objects in a viscous fluid. Specifically, the dynamics of a micron-scale cylinder oscillating in water are studied numerically. The fluid dynamics generated by an infinitely long cylinder are a good approximation for the flow field around an oscillating cantilever. The numerical results agree well with analytical theory. It is anticipated that further development of the fully Lagrangian numerical approach for fluid-solid interaction problems will be useful in the development of micro and nano-technologies.


2021 ◽  
pp. 107754632110233
Author(s):  
Lemiao Qiu ◽  
Guannan Su ◽  
Zili Wang ◽  
Shuyou Zhang ◽  
Lichun Zhang ◽  
...  

High-speed elevator horizontal vibration seriously affects passenger comfort. To reach the smooth operation of the high-speed elevators, it is extremely important to study the horizontal vibration of the elevator car. There are two main factors that cause the horizontal vibration of the high-speed elevator car, namely, the guidance system excitations and the car aerodynamic characteristics running in the hoistway. Under the coupling action of these two factors, the horizontal vibration of the high-speed elevator car system is aggravated. To accurately obtain the horizontal vibration information of the high-speed elevator, we developed the high-speed elevator car horizontal vibration fluid–solid interaction model. It is decoupled by the proposed fluid–solid interaction decoupling solution. The influence of the high-speed elevator running speed, the guide rail profile deviation, and the rolling guide shoe dynamic parameters on the car horizontal vibration is analyzed. To verify the feasibility of the proposed method, the 5 m/s, 7 m/s, 8 m/s, and 10 m/s high-speed elevators are applied in a 288 m test tower. The simulation accuracy using the proposed method reaches the minimum of 0.93% in 5 m/s case of the peak-to-peak value, reaches the minimum of 3.11% in 10 m/s case of the A95 value, and reaches the minimum of 0.13% in 10 m/s case of the main frequency value. In general, the compared results of the peak-to peak vibration acceleration, the A95 value, and the main frequency are all closed in both 5 m/s, 7 m/s, 8 m/s, and 10 m/s cases.


Author(s):  
O.N Goncharova ◽  
◽  
I.V. Marchuk ◽  
A.V. Zakurdaeva ◽  
◽  
...  

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 145-153 ◽  
Author(s):  
Chengua Yu ◽  
Feng Wang ◽  
Shiyu Fu ◽  
Lucian Lucia

A very low-density oil-absorbing hydrophobic material was fabricated from cellulose nanofiber aerogels–coated silane substances. Nanocellulose aerogels (NCA) superabsorbents were prepared by freeze drying cellulose nanofibril dispersions at 0.2%, 0.5%, 0.8%, 1.0%, and 1.5% w/w. The NCA were hydrophobically modified with methyltrimethoxysilane. The surface morphology and wettability were characterized by scanning electron microscopy and static contact angle. The aerogels displayed an ultralow density (2.0–16.7 mg·cm-3), high porosity (99.9%–98.9%), and superhydrophobicity as evidenced by the contact angle of ~150° that enabled the aerogels to effectively absorb oil from an oil/water mixture. The absorption capacities of hydrophobic nanocellulose aerogels for waste engine oil and olive oil could be up to 140 g·g-1 and 179.1 g·g-1, respectively.


1996 ◽  
Vol 451 ◽  
Author(s):  
T. Shimizu ◽  
M. Murahara

ABSTRACTA Fluorocarbon resin surface was selectively modified by irradiation with a ArF laser beam through a thin layer of NaAlO2, B(OH)3, or H2O solution to give a hydrophilic property. As a result, with low fluence, the surface was most effectively modified with the NaAlO2 solution among the three solutions. However, the contact angle in this case changed by 10 degrees as the fluence changed only 1mJ/cm2. When modifying a large area of the surface, high resolution displacement could not be achieved because the laser beam was not uniform in displacing functional groups. Thus, the laser fluence was successfully made uniform by homogenizing the laser beam; the functional groups were replaced on the fluorocarbon resin surface with high resolution, which was successfully modified to be hydrophilic by distributing the laser fluence uniformly.


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