Готові списки джерел за темами / Washburn's equation / Статті в журналах

Статті в журналах з теми "Washburn's equation"

Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Washburn's equation.
Автор: Grafiati
Опубліковано: 14 травня 2022

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся з топ-50 статей у журналах для дослідження на тему "Washburn's equation".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.

1

Labajos-Broncano, L., M. L. González-Martı&#x;n, and J. M. Bruque. "Washburn's Equation Facing Galileo's Transformation: Some Remarks." Journal of Colloid and Interface Science 253, no. 2 (September 2002): 472–74. http://dx.doi.org/10.1006/jcis.2002.8521.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Chibowski, Emil, and Lucyna Hołysz. "On the use of Washburn's equation for contact angle determination." Journal of Adhesion Science and Technology 11, no. 10 (January 1997): 1289–301. http://dx.doi.org/10.1163/156856197x00147.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Ramesh, Babu V., G. Ramakrishnan, V. S. Subramanian, and Lakshmi Kantha. "Analysis of Fabrics Structure on the Character of Wicking." Journal of Engineered Fibers and Fabrics 7, no. 3 (September 2012): 155892501200700. http://dx.doi.org/10.1177/155892501200700305.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In this article, the effect of weave pattern on fabric wicking was analyzed. Weaves are distributed into two groups, i.e. weaves, the floats of which are distributed in even intervals throughout the entire surface of fabric, and horizontally striped weaves. The wickability properties of all tested fabrics are determined using a newly developed electronic vertical wicking tester. It was determined that the results of wicking horizontally striped fabrics were higher than those of weaves with evenly distributed floats. Washburn's equation obeyed quite well when the time constant is near 0.5. In fact, the time constant for plain and fancy twill weave were exponentially lower than those of other fabrics. This can be considered a measure of fabric rigidity.
4

Labajos-Broncano, L., M. L. González-Martín, J. M. Bruque, and C. M. González-García. "Comparison of the Use of Washburn's Equation in the Distance–Time and Weight–Time Imbibition Techniques." Journal of Colloid and Interface Science 233, no. 2 (January 2001): 356–60. http://dx.doi.org/10.1006/jcis.2000.7283.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Labajos-Broncano, L., M. L. González-Martı́n, J. M. Bruque, C. M. González-Garcı́a, and B. Jańczuk. "On the Use of Washburn's Equation in the Analysis of Weight–Time Measurements Obtained from Imbibition Experiments." Journal of Colloid and Interface Science 219, no. 2 (November 1999): 275–81. http://dx.doi.org/10.1006/jcis.1999.6492.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Ji, Lingyun, and Baoli Shi. "A novel method for determining surface free energy of powders using Washburn's equation without calculating capillary factor and contact angle." Powder Technology 271 (February 2015): 88–92. http://dx.doi.org/10.1016/j.powtec.2014.11.002.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Alsamia, Shaymaa, Mohammed Sh Mahmood, and Ali Akhtarpour. "Estimation of capillary rise in unsaturated gypseous sand soils." Pollack Periodica 15, no. 2 (August 2020): 118–29. http://dx.doi.org/10.1556/606.2020.15.2.11.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
AbstractThe phenomenon of capillary rise happens in soils, and it has a crucial effect on many engineering applications. Many researchers have concluded several experimental equations to estimate this height. This paper presents a comparative and practical study of the three most important equations used in most researches, which are Lane and Washburn, Fetter, and P-K equations. The estimated heights by these three equations were compared with the experimental tests on sand samples taken from Al-Adalah, Al-Furat, and Al-Jameah districts located in Al-Najaf city in the southwest of Iraq. The percentage change for each equation compared with the experimental work. The results illustrated that the Fetter equation is the closest equation to experimental height and gives moderate values, unlike the Lane and Washburn and P-K equations, to save estimation of the pollutants penetration in unsaturated soils.
8

DASARATHAN, KAMALRAJ, and SUBRAMANIAM VENKATRAMAN. "Validity of Washburn’s equation in sericin treated polyester fabric." Industria Textila 70, no. 01 (March 1, 2019): 94–97. http://dx.doi.org/10.35530/it.070.01.1537.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Application of sericin to polyester and cotton fabrics will bring about a number of advantages in that the materials become hydrophilic and are capable of imparting antimicrobial effect. Also, the materials can be dyed using reactive dyes. A considerable amount of work has been carried out on the application of sericin to polyester and cotton fabrics. Wickability of treated fabrics has been studied and it was demonstrated that there was an improvement. A detailed analysis of study is warranted on wickability as the work done on it was scant. It is necessary to validate Washburn’s equation which constitutes an important component of kinetics of wicking in this paper. The validity of Washburn’s equation for a set of data on wickability of sericin treated polyester fabrics is studied. Untreated polyester fabric and treated with caustic soda and plasma followed by sericin treatment using DMDHEU and Glutaraldehyde were taken for wicking studies. Two models were used. From the slopes it is found that Washburn’s equation is followed.
9

SĘK, Jerzy, Olga S. SHTYKA, and Kamila SZYMCZAK. "MODELING OF THE SPONTANEOUS POLYPROPYLENE SORBENTS IMBIBITION WITH EMULSIONS." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 23, no. 2 (December 13, 2014): 83–93. http://dx.doi.org/10.3846/16486897.2014.961926.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Oil penetration into aqueous media results in various chemical and physical processes including formation of “oil-in-water” emulsions, that have devastating effects on the environment. This research was conducted to evaluate the kinetics of permeation of “oil-in-water” emulsions into synthetic porous material. It gives the ability to develop more effective sorbents, decreasing risks of negative consequences and environmental contamination. The following publication focuses on assessment of the possibility to describe and predict a process of porous medium imbibition with emulsions by means of the Hill equation. Its adequacy is compared with the classical Lucas–Washburn equation and its modified version. The advanced approach is to substitute the commonly used parameter of the height of an imbibed emulsion (h(t)) by the parameter mh(t), which is the mass of an imbibed emulsion in the case of the classical and modified Washburn equations. According to the obtained results, the Hill equation provides the most appropriate and precise description of the porous material imbibition with “oil-in-water” emulsions and oil in comparison with others, and shows the highest correlation values (Rav = 0.995±0.001) and the lowest normalized root mean square error (NRMSEav 1.95±0.138).
10

Villagrán Zaccardi, Yury, Natalia Alderete, and Nele De Belie. "Lucas-Washburn vs Richards equation for the modelling of water absorption in cementitious materials." MATEC Web of Conferences 199 (2018): 02019. http://dx.doi.org/10.1051/matecconf/201819902019.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The Lucas-Washburn equation is still being applied by a significant number of researchers for the modelling of water absorption in cementitious materials. A modern approach considers the extended Darcy’s law leading to the Richards equation instead. Three main assumptions are implied by the application of the Lucas-Washburn equation: the flow occurs in one direction only, the material is separated into one fully wet and one fully dry region, and pores are modelled as an assembly of parallel tubes of a particular radius. Its application to analyse experimental results allows defining these three assumptions as mere simplifications. Therefore, all the parameters comprised in the Lucas-Washburn model are apparent. Consequently, a very limited description of the transport properties of the material can be achieved. For many engineering purposes this would not be an issue, but for an intrinsic description of the material a more realistic model is required. This paper discusses the limitations of the Lucas-Washburn equation, and the advantages of the Richards equation regarding the modelling of water absorption in cementitious materials. The comparative analysis reveals the versatility of the Richards equation, with an approach that considers the material as a continuum and describes it through measurable parameters.
11

Chang, Sooyoung, Jaedeok Seo, Seokbin Hong, Duck-Gyu Lee, and Wonjung Kim. "Dynamics of liquid imbibition through paper with intra-fibre pores." Journal of Fluid Mechanics 845 (April 20, 2018): 36–50. http://dx.doi.org/10.1017/jfm.2018.235.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
We present a combined experimental and theoretical investigation of the dynamics of liquid imbibition through paper. The Washburn equation is widely used to describe the dynamics of capillary flow through paper, but this classical model has limited accuracy, which often makes it difficult to use in developing analytic systems such as paper-based microfluidic devices. We here report that the internal cavity of the cellulose fibres composing paper is significantly responsible for the limited accuracy of the Washburn equation. Our experiments demonstrated that liquid can be absorbed in the internal cavity of the cellulose fibres as well as in the inter-fibre pores formed by the fibre network. We developed a mathematical model for liquid imbibition by considering the flow through the intra-fibre pores based on experimental measurements of the intra-structure of cellulose fibres. The model markedly improves the prediction of the liquid absorption length, compared with the results of the Washburn equation, thus revealing the physics behind the limits of the Washburn equation. This study suggests that the accurate description of capillary imbibition through paper require parameters characterizing the internal pores of the cellulose fibres comprising the paper. Our results not only provide a new insight into porous media flows with different sized pores, but also provide a theoretical background for flow control in paper-based microfluidic systems.
12

Hamraoui, Ahmed, and Tommy Nylander. "Analytical Approach for the Lucas–Washburn Equation." Journal of Colloid and Interface Science 250, no. 2 (June 2002): 415–21. http://dx.doi.org/10.1006/jcis.2002.8288.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
13

Kadlec, Ondřej. "The influence of dispersion forces on the mercury intrusion into pores of solids." Collection of Czechoslovak Chemical Communications 50, no. 12 (1985): 2788–803. http://dx.doi.org/10.1135/cccc19852788.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
On the basis of the Gibbs condition of thermodynamic equilibrium of heterogeneous system occuring in a force field, a general expression is derived for the dependence of the liquid mercury pressure on an equivalent radius of pores volume-filled on its intrusion. For the equivalent radius r of pores greater than 30 nm, this equation turns into the well-known Washburn equation. It is shown that for pores of equivalent radii smaller than 5 nm, the presence of dispersion forces is the reason of considerable deviations from the classical Washburn equation. The effect of the liquid mercury pressure on the contact angle θ of intruded mercury with pore walls is also discussed.
14

Jackson, P. V., J. A. Hunt, P. J. Doherty, A. Cannon, and P. Gilson. "Hydrophilicity of 3-D biomaterials: The Washburn equation." Journal of Materials Science: Materials in Medicine 15, no. 4 (April 2004): 507–11. http://dx.doi.org/10.1023/b:jmsm.0000021129.60818.ca.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
15

Hanžič, Lucija, Ladislav Kosec, and Ivan Anžel. "Capillary absorption in concrete and the Lucas–Washburn equation." Cement and Concrete Composites 32, no. 1 (January 2010): 84–91. http://dx.doi.org/10.1016/j.cemconcomp.2009.10.005.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
16

Chu, Kang-Ching, Heng-Kwong Tsao, and Yu-Jane Sheng. "Penetration dynamics through nanometer-scale hydrophilic capillaries: Beyond Washburn’s equation and extended menisci." Journal of Colloid and Interface Science 538 (March 2019): 340–48. http://dx.doi.org/10.1016/j.jcis.2018.12.005.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
17

Shishatsky, J. I., A. M. Barbashin, and S. A. Nickel. "Development of mathematical model of extraction from lupine with cheese serum by applying low-frequency mechanical vibrations." Proceedings of the Voronezh State University of Engineering Technologies 81, no. 1 (July 18, 2019): 36–41. http://dx.doi.org/10.20914/2310-1202-2019-1-36-41.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
It is noted that the model is designed to create the largest possible pressure change in the cheese whey in the extractor, since the rate of transfer of the target components is proportional to the pressure difference at the ends of the capillaries. The mathematical description of impregnation as the main or important auxiliary operation is given in detail. The equations for the impregnated part of the capillary, the ratio of impregnation rates at different times are given. From the above dependencies, the equation Washburne regarding the time of impregnation. The formulas for calculating the volume of extractant passed through the capillary, serum and forced out of the capillary air taking into account the viscous resistance of the latter. After integration of the equation of the speed of capillary impregnation of the obtained expression allows to estimate the final value of the impregnation in the initial stage. For different cases of capillary impregnation expressions are written at atmospheric pressure, vacuuming and overpressure. The introduction of dimensionless values allowed to simplify the solution and to obtain an expression for calculating the time of pore impregnation. The analysis of the equation of dimensionless impregnation time taking into account the application of low-frequency mechanical vibrations is made. It is noted that the processes of impregnation and extraction occur simultaneously, so the impregnation time is often neglected, which impoverishes the understanding of the physics of the process, reduces the accuracy of the calculation. Taking into account the diffusion unsteadiness of the process of substance transfer due to hydrodynamic unsteadiness, the equation containing the effective diffusion coefficient is written. The equation of unsteady diffusion for a spherical lupine particle in a batch extractor is supplemented with initial and boundary conditions. Taking into account the balance equation, the kinetic equation of the process is obtained. We studied the distribution of pores in the particle lupine along the radii and squares, the calculated value of the porosity of the particle. The values of De and Bi are determined by the method of graphical solution of the balance equation, the equation of kinetics and the parameters included in these equations. Conclusions on the work.
18

Chibowski, Emil, and Lucyna Holysz. "Use of the Washburn equation for surface free energy determination." Langmuir 8, no. 2 (February 1992): 710–16. http://dx.doi.org/10.1021/la00038a066.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
19

Cai, Jianchao, Tingxu Jin, Jisheng Kou, Shuangmei Zou, Junfeng Xiao, and Qingbang Meng. "Lucas–Washburn Equation-Based Modeling of Capillary-Driven Flow in Porous Systems." Langmuir 37, no. 5 (January 29, 2021): 1623–36. http://dx.doi.org/10.1021/acs.langmuir.0c03134.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
20

Yang, Ya-Wun, and George Zografi. "Use of the Washburn—Rideal Equation for Studying Capillary Flow in Porous Media." Journal of Pharmaceutical Sciences 75, no. 7 (July 1986): 719–21. http://dx.doi.org/10.1002/jps.2600750723.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
21

Zhang, Xiao Dan, Jun Hao Qian, and Jun Wei Jia. "Ink Penetration Model Research Based on Ink Permeability." Applied Mechanics and Materials 731 (January 2015): 462–65. http://dx.doi.org/10.4028/www.scientific.net/amm.731.462.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
This article analyzes the mechanism of interaction between the ink and paper. The Washburn equation just based on static penetration, while in contact with the ink and paper, freedom infiltration process is a dynamic process. So it is further derived based on a model of the dynamic ink permeability of dynamic contact angle, and mathematical analyzes some of the important parameters of the dynamic model so that can strive a more accurate description of the state of penetration of ink into the paper, thereby theoretically predict the quality control of printed matter.
22

Qu, Zhen Cai, Guang Xue Chen, Bao Lin Tang, and Shuang Shuang Wen. "Study on Model of Dot Gain in Ink-Jet Printing." Advanced Materials Research 236-238 (May 2011): 1405–9. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1405.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Ink-jet printing is a non-contact printing, drops are jetted on the substrates to form images through the nozzles at a certain speed. Dot is the smallest unit in printing; the qualities of printing are seriously affected by dot gain. Ink spreading and penetration are discussed in this paper, influences on dot gain in ink-jet printing are studied, the original Young's equation and Washburn formula are theoretically amended, more scientific and rational models and formulas are obtained in the actual process of ink-jet printing, which offers reference standard and theoretical basis to improve the quality of ink-jet printing.
23

Sorbie, K. S., Y. Z. Wu, and S. R. McDougall. "The Extended Washburn Equation and Its Application to the Oil/Water Pore Doublet Problem." Journal of Colloid and Interface Science 174, no. 2 (September 1995): 289–301. http://dx.doi.org/10.1006/jcis.1995.1394.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
24

Chang, Qing, Bin Wu Yang, and Bi Gui Wei. "Effects of Wettability and Zeta Potential of Filter Medium on Oil Removal." Advanced Materials Research 148-149 (October 2010): 58–70. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.58.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The methods and devices which can be used to determine the wettability and zeta potential of filter medium were developed according to the principles of capillary rise and streaming potential respectively. Lipophilic Hydrophilic Ratio (LHR) was defined based on Washburn equation. LHR values and zeta potentials of some conmen filter media were measured respectively, and the oil removal efficiencies of these filter media were also tested. The result shows that the effect of wettability on oil removal efficiency is much greater than that of zeta potential in conmen condition. The oil removal efficiency mainly depends on LHR value of filter medium, not on zeta potential of filter medium.
25

Pirard, R., S. Blacher, F. Brouers, and J. P. Pirard. "Interpretation of mercury porosimetry applied to aerogels." Journal of Materials Research 10, no. 8 (August 1995): 2114–19. http://dx.doi.org/10.1557/jmr.1995.2114.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The observation of aerogels submitted to a pressure of mercury indicates that this porous material is compacted and not intruded by the mercury. Consequently, the classical Washburn equation cannot be applied. A relation is established between the pressure P of compaction and the size L of the largest pores. The size of pores is estimated by using the nitrogen adsorption-desorption isotherms analysis and SEM measurements. A relation is found in which P is proportional to L−4 The new relation is applied to mercury porosimetry. Finally, a mechanical model is proposed that reproduces successfully the behavior of aerogels under high pressure of mercury.
26

Rigby, Sean P., David Barwick, Robin S. Fletcher, and Sandra N. Riley. "Interpreting mercury porosimetry data for catalyst supports using semi-empirical alternatives to the Washburn equation." Applied Catalysis A: General 238, no. 2 (January 2003): 303–18. http://dx.doi.org/10.1016/s0926-860x(02)00348-4.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
27

Ichikawa, Chiaki, Takahiro Fukunaga, Daitaro Ishikawa, and Tomoyuki Fujii. "Whipping Behavior of Rice Flour Dough." MATEC Web of Conferences 333 (2021): 02008. http://dx.doi.org/10.1051/matecconf/202133302008.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In this study, the bubbles in rice flour dough were investigated under a constant temperature. The bubble size distribution is important for the control of food texture. If bubble sizes depend mainly on the inertial force, viscous force, and surface tension, then the normalized mean bubble diameter should be a function of the Reynolds number and Weber number. We obtained experimental data using a hand mixer, and compared the properties of doughs prepared using six rice flours; each flour was prepared through a different milling process. We also added the size effect of the rice flour particles as the Bond number. Furthermore, we performed a dynamic wettability test to estimate the wettability of the rice flour surface. The results of this test were described well by the Washburn equation, and dccosθ was calculated as a wettability parameter (where, dc: effective diameter of a capillary in a powder bed, cosθ: the contact angle). The mean bubble diameter (dbm) generated by whipping was expected to be affected by the thickness (d) of the rod of the mixer, its movement speed, physical properties of the material, and gravitational acceleration. Therefore, dimensionless mean diameter (dbm/d) was expressed by a dimensionless equation. The empirical equation obtained was generally applicable to the variety of materials selected for this study.
28

Ichikawa, Chiaki, Takahiro Fukunaga, Daitaro Ishikawa, and Tomoyuki Fujii. "Whipping Behavior of Rice Flour Dough." MATEC Web of Conferences 333 (2021): 02008. http://dx.doi.org/10.1051/matecconf/202133302008.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In this study, the bubbles in rice flour dough were investigated under a constant temperature. The bubble size distribution is important for the control of food texture. If bubble sizes depend mainly on the inertial force, viscous force, and surface tension, then the normalized mean bubble diameter should be a function of the Reynolds number and Weber number. We obtained experimental data using a hand mixer, and compared the properties of doughs prepared using six rice flours; each flour was prepared through a different milling process. We also added the size effect of the rice flour particles as the Bond number. Furthermore, we performed a dynamic wettability test to estimate the wettability of the rice flour surface. The results of this test were described well by the Washburn equation, and dccosθ was calculated as a wettability parameter (where, dc: effective diameter of a capillary in a powder bed, cosθ: the contact angle). The mean bubble diameter (dbm) generated by whipping was expected to be affected by the thickness (d) of the rod of the mixer, its movement speed, physical properties of the material, and gravitational acceleration. Therefore, dimensionless mean diameter (dbm/d) was expressed by a dimensionless equation. The empirical equation obtained was generally applicable to the variety of materials selected for this study.
29

Lekobou, William P., Karl R. Englund, Marie-Pierre Laborie, and Patrick D. Pedrow. "Influence of atmospheric pressure plasma treatments on the surface properties of ligno-cellulosic substrates." Holzforschung 70, no. 1 (January 1, 2016): 55–61. http://dx.doi.org/10.1515/hf-2014-0211.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
AbstractThe paper aims at the investigation of atmospheric pressure weakly ionized plasmas with argon and acetylene to deposit plasma-polymerized coatings on wood veneers (birch, maple), cellulose paper, and pine wood flour to modify their surface properties, in particular their topography and wettability. The treatment was performed in a reactor containing an array of high-voltage needles and a grounded metallic mesh as electrodes. The deposition occurred in the discharge downstream of the plasma region. The plasma-polymerized acetylene deposits form spherical nodules on the surface of the substrates and change their wettability from hydrophilic to hydrophobic. The water contact angles of the veneer were determined with a goniometer. The capillary rise was combined with the Washburn equation to assess the change in hydrophilicity of the plasma-treated wood flour.
30

Chatterjee, Arobindo, and Pratibha Singh. "Studies on Wicking Behaviour of Polyester Fabric." Journal of Textiles 2014 (February 24, 2014): 1–11. http://dx.doi.org/10.1155/2014/379731.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
This paper aims to investigate vertical wicking properties of polyester fabric based on change in sample direction and change in tension. Also experimental results are compared with theoretical results. Polyester fabric made out of spun yarn with four types of variation in pick density was used. Theoretical values of vertical wicking were calculated by using Lucas-Washburn equation and experimental results were recorded using strip test method. Maximum height reached experimentally in both warp way and weft way is more than that of the theoretical values. The maximum height attained by fabric experimentally in weft is more as compared to warp way. Vertical wicking increases with increase in tension. This paper is focused on wicking which plays a vital role in determining comfort and moisture transport behavior of fabric.
31

O’Loughlin, M., K. Wilk, C. Priest, J. Ralston, and M. N. Popescu. "Capillary rise dynamics of aqueous glycerol solutions in glass capillaries: A critical examination of the Washburn equation." Journal of Colloid and Interface Science 411 (December 2013): 257–64. http://dx.doi.org/10.1016/j.jcis.2013.05.077.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
32

Temirel, Mikail, Sajjad Rahmani Dabbagh, and Savas Tasoglu. "Hemp-Based Microfluidics." Micromachines 12, no. 2 (February 12, 2021): 182. http://dx.doi.org/10.3390/mi12020182.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Hemp is a sustainable, recyclable, and high-yield annual crop that can be used to produce textiles, plastics, composites, concrete, fibers, biofuels, bionutrients, and paper. The integration of microfluidic paper-based analytical devices (µPADs) with hemp paper can improve the environmental friendliness and high-throughputness of µPADs. However, there is a lack of sufficient scientific studies exploring the functionality, pros, and cons of hemp as a substrate for µPADs. Herein, we used a desktop pen plotter and commercial markers to pattern hydrophobic barriers on hemp paper, in a single step, in order to characterize the ability of markers to form water-resistant patterns on hemp. In addition, since a higher resolution results in densely packed, cost-effective devices with a minimized need for costly reagents, we examined the smallest and thinnest water-resistant patterns plottable on hemp-based papers. Furthermore, the wicking speed and distance of fluids with different viscosities on Whatman No. 1 and hemp papers were compared. Additionally, the wettability of hemp and Whatman grade 1 paper was compared by measuring their contact angles. Besides, the effects of various channel sizes, as well as the number of branches, on the wicking distance of the channeled hemp paper was studied. The governing equations for the wicking distance on channels with laser-cut and hydrophobic side boundaries are presented and were evaluated with our experimental data, elucidating the applicability of the modified Washburn equation for modeling the wicking distance of fluids on hemp paper-based microfluidic devices. Finally, we validated hemp paper as a substrate for the detection and analysis of the potassium concentration in artificial urine.
33

Zhang, Derun, and Rong Luo. "An alternative method to evaluate the surface free energy of mineral fillers based on the generalized Washburn equation." Construction and Building Materials 231 (January 2020): 117164. http://dx.doi.org/10.1016/j.conbuildmat.2019.117164.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
34

Sun, Yueting, Jun Xu, Yibing Li, Xiaoqing Xu, Cheng Liu, and Xi Chen. "Mechanism of Water Infiltration and Defiltration through ZSM-5 Zeolite: Heating and Sodium Chloride Concentration Effect." Journal of Nanomaterials 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/249369.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Hydrophobic nanoporous material and wetting liquid together comprise a system with promising energy related applications. The mechanism of the interaction between liquid and solid phase is not fully explored. In this paper, based on the quasistatic compression experiments on investigating the mechanical behavior of ZSM-5 zeolite/NaCl solution system, the effects of two key parameters, that is, the pretreatment temperature of ZSM-5 zeolite and NaCl concentration, are parametrically and quantitatively investigated based on Laplace-Washburn equation. Results show that both pretreatment temperature and NaCl concentration raise the infiltration pressure and NaCl can also promote defiltration. The advancing contact and receding contact angle of zeolite-NaCl-air system increase with both pretreatment temperature and NaCl concentration, and the contact angle hysteresis decreases with NaCl concentration. Results may provide fundamental explanation to the nanoconfined liquid behavior and liquid-solid interaction, thus, to smartly control the mechanical properties of the liquid spring and bumpers for energy dissipation function.
35

MacDonald, Brendan D. "Flow of liquids through paper." Journal of Fluid Mechanics 852 (August 2, 2018): 1–4. http://dx.doi.org/10.1017/jfm.2018.536.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The flow of liquids through paper is challenging to model due to the complexity and disordered layout of the fibre matrix. The expanding use and capability of microfluidic paper-based analytical devices ($\unicode[STIX]{x1D707}$PADs) and their requirement for precision has increased the need to accurately predict the flow of liquids through paper. Many studies have developed models and revealed some of the physical mechanisms responsible for the flow behaviour, but we still lack a complete understanding, particularly in relation to how the fluid fills the various voids with a wide range of shapes and sizes in the fibre matrix of paper. In the featured article, Chang et al. (J. Fluid Mech., vol. 845, 2018, 36–50) used a combined experimental and theoretical approach to uncover the importance of the liquid filling the intra-fibre pores, showed that this results in deviation from the flow behaviour predicted by the Lucas–Washburn equation and developed a model which accounts for this effect.
36

Ravandi, Seyed Abdolkarim Hosseini, Razieh Hashemi Sanatgar, and Farzad Dabirian. "Wicking Phenomenon in Nanofiber-Coated Filament Yarns." Journal of Engineered Fibers and Fabrics 8, no. 3 (September 2013): 155892501300800. http://dx.doi.org/10.1177/155892501300800302.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Wicking phenomenon has been investigated in filaments and spun yarns in different studies. In comparison with conventional structures, nanofibrous structures have unique characteristics such as higher surface-to-volume ratios, smaller pores, and higher porosity. For many nanofiber applications, a good understanding of the liquid absorption and wettability of nanofibrous is crucial. In this article, a modified electrospinning process for yarn coating with nanofiber is presented. In this method, fiber direction was controlled by manipulating the conventional system of electrospining and embedded nanofibers on yarn surface. Nylon66 filament was coated with nylon 66 nanofiber. The coating morphology and capillary phenomenon were examined in different concentrations of polymer solution. The kinetics of capillary flow of colored liquid in coated yarns with nanofiber follows the Lucas-Washburn equation. Results show that coating with nanofibers increases equilibrium wicking height. In a nanofiber coating process, with a constant feeding rate, increasing the solution concentration increases the capillary rise rate.
37

Nie, Gaofa, Xuhong Miao, Yuhang Tang, and Qian Chen. "Implementation and Experiment of a Novel Molecular Spring Isolator." Shock and Vibration 2022 (April 7, 2022): 1–9. http://dx.doi.org/10.1155/2022/7174089.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
A molecular spring isolator comprising ZIF-8 with hydrophobic micropores, water, and a cylinder/piston unit is introduced. Liquid water can be intruded into the micropores of ZIF-8 under critical pressure. In the meantime, mechanical energy is stored. And once the external pressure is withdrawn, spontaneous capillary evaporation will occur. The stored energy, meanwhile, is released. This behavior is similar to a coil spring. The Laplace–Washburn equation is used to describe the force equilibrium of a single water column in a micropore. After that, the result of water infiltrating a great deal of hydrophobic pores is revealed by theoretical analysis and an experiment. An averaging method is devoted to computing the primary resonance response and its accuracy is proved by the fourth-order Runge–Kutta method. Furthermore, the energy transmissibility is used to estimate its vibration isolation capability. Finally, a vibration isolation test indicated that the inherent frequency of the isolator is as low as 1.3 Hz.
38

HAMADA, HITOMI, and DOUGLAS W. BOUSFIELD. "Nanofibrillated cellulose as a coating agent to improve print quality of synthetic fiber sheets." November 2010 9, no. 11 (December 1, 2010): 25–29. http://dx.doi.org/10.32964/tj9.11.25.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
To determine the potential of nanofibrillated cellulose (NFC) for use as a coating material, we studied the characteristics of several NFC-coated samples on a synthetic fiber sheet. We used two water-based printing methods to characterize the change in print quality and prepared two types of NFC by two different physical treatment methods. Various coat weights were applied onto synthetic fiber sheets, and the printability of the coated sheets was evaluated by ink absorption rates and print density. Ink pigment penetration was characterized with a confocal laser scanning microscope and a scanning electron microscope, with chemical analysis of samples using focused ion beam. The contact angle and the ink penetration rates decreased with increased coat weight of NFC. This result is the opposite of what the Lucas-Washburn equation would predict. For pigment-based flexographic inks, ink pigments were captured at the NFC layer. For dye-based inks, the ink components penetrated and moved through the NFC-coated layer. For ink-jet printing, the print quality improved with the NFC coating.
39

Song, Kai Wei, Guo Fu Chen, Hang Zhang, Cong Li Shi, and Jia Yang. "Mechanism Research of Drying Shrinkage of Cement Pastes Based on the Contact Angle." Applied Mechanics and Materials 670-671 (October 2014): 391–95. http://dx.doi.org/10.4028/www.scientific.net/amm.670-671.391.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Capillary tention is one of the driving forces of shrinkage of cement-based materials, which is related to distribution of pore size, surface tension of pore water, contact angle of pore walls and so on. There are some appropriate test methods for pore diameter and surface tension of cement-based materials, but the contact angle of pore water is rarely related to. This paper showed a new method to test the contact angle of cement-based materials which is based on the principle of thin-layer wicking about surface physical chemistry. Combining Washburn equation x2=(Refft/2) , the contact angle of analog pore solution to cement paste was obtained. The influence of superplasticizers and mineral admixtures on the contact angle and drying shrinkage of cement pastes also were researched. The results showed that the larger contact angle leads to the smaller surface tension of pore solution, which also caused that the capillary wall wass infiltrated more difficultly. As a result, the pressure of pore and the drying shrinkage were both small, vice versa.
40

Cai, Shaobin, Li Zhang, Lixin Kang, Yongfei Yang, Wenlong Jing, Lei Zhang, Chao Xu, Hai Sun, and Mozhdeh Sajjadi. "Spontaneous Imbibition in a Fractal Network Model with Different Wettabilities." Water 13, no. 17 (August 29, 2021): 2370. http://dx.doi.org/10.3390/w13172370.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In this work, we derived a mathematical model for spontaneous imbibition in a Y-shaped branching network model. The classic Lucas–Washburn equation was used for modeling the imbibition process occurring in the Y-shape model. Then, a mathematical model for the Newtonian fluid’s imbibition was derived to reveal the relationship between dimensionless imbibition time and length ratio, radius ratio, and wetting strength. The dimensionless imbibition time in the model was adopted to compare with that of the capillary bundle model. Different length and radius ratios were considered in the adjacent two-stage channels, and different wettabilities were considered in the different branches. The optimal radius ratio, length ratio, and wetting strength were calculated under the condition of the shortest imbibition time. In addition, the shortest dimensionless imbibition time of the three-stage Y-shaped branching network model was calculated when the wettability changes randomly. The results indicate that the imbibition time changed mostly when the wettability of the second branch changed, and the second branch was the most sensitive to wettability in the model.
41

Jaunslavietis, Jevgenijs, Galia Shulga, Jurijs Ozolins, Brigita Neiberte, Anrijs Verovkins, Sanita Vitolina, and Talrits Betkers. "Hydrophilic-Hydrophobic Characteristics of Wood-Polymer Composites Filled with Modified Wood Particles." Key Engineering Materials 762 (February 2018): 176–81. http://dx.doi.org/10.4028/www.scientific.net/kem.762.176.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In this study, hydrophobic-hydrophilic characteristics, including contact angle and moisture sorption of a modified wood filler and the wood-polymer composites (WPC) containing it was investigated. The wood filler obtained from aspen sawdust was modified by mild acid hydrolysis and by ammoxidation. Contact angles of the wood particles and the WPC samples were measured with Kruss K100M using the Washburn and Wilhelmy methods, respectively. Work of adhesion was calculated using Young-Dupre equation. Surface free energy as well as its dispersive and polar parts were found using Owens-Wendt-Rabel-Kaelble approach. It was found that the hydrolysis and the ammoxidation led to decrease of the hemicelluloses content in the lignocellulosic matrix. Beside this, the ammoxidation favours the formation of amide bonds in the ammoxidised particles. These changes enhanced the contact angles, decreased the work of adhesion, and decreased surface free energy of the WPC samples filled with the modified particles in comparison with the WPC sample that contained the unmodified ones. The treatment of the wood particles decreased the wettability towards water, but increased it towards recycled polypropylene. This positively effects mechanical properties of the samples.
42

Hadnadjev-Kostic, Milica, Arpad Kiralj, and Dunja Sokolovic. "Wettability investigation of stainless steel fibers with mineral oils using the modified method for liquid penetration kinetics." Acta Periodica Technologica, no. 49 (2018): 53–64. http://dx.doi.org/10.2298/apt1849053h.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The modified Washburn equation and the lipophilic/hydrophilic (L/H) ratio are most commonly used for the wettability characterization of fibers. Therefore, this liquid penetration method was applied for the wettability investigation of stainless steel fibers with mineral oils and the lipophilic/hydrophilic (L/H) ratio was obtained. As test liquids mineral oils and water were used. It was found that the range of L/H ratio values was vastly broad (from 1048340 to 37802) concluding that this liquid penetration method was not suitable for these particular fibers. Consequently, in this study a modified method was developed defining a novel route to filter media wettability characterization and establishing the lipophilic/lyophobic ratio (LLR). As the new reference liquid the medical, white oil was selected. By using polar mineral oils the interval of the LLR ratio for stainless steel fibers ranged from 1 to 28. It can be concluded that the suggested LLR ratio, was adequately selected as a measure of wettability for stainless steel fibers with mineral oils. The LLR ratio exponentially increased with the increase of the neutralization number and viscosity of investigated mineral oils.
43

Wiącek, Agnieszka Ewa, and Kacper Przykaza. "Wettability and Stability of Naproxen, Ibuprofen and/or Cyclosporine A/Silica Delivery Systems." Colloids and Interfaces 6, no. 1 (February 6, 2022): 11. http://dx.doi.org/10.3390/colloids6010011.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The characteristics of the wetting process of the porous surface of silica gel when penetrated by base liquids (water and n-octane), ethanol and stable drug systems (naproxen, ibuprofen and cyclosporine A), as biologically active substances in two ethanol concentrations, were determined by the wetting rate vs. time. The tests were performed for contacted and non-contacted plates with the vapours of the wetting liquid. Thin-layer liquid chromatography was used to determine the penetration rate of the SiO2-coated plates, taking into account the linear dependence consistent with the Washburn equation. Additionally, the changes in the adhesive tension ΔG were determined for the tested drugs. Drug stability tests were conducted using the dynamic light scattering technique and microelectrophoresis. The penetration time of the plate depends on the properties and structure of the wetting liquid droplets. The types of interactions (dispersive, electrostatic and hydrogen bonding) formed between the silanol surface groups of the silica gel and the groups contained in the adsorbate particles are also very important factors. The greater the impact force, the slower the wetting process due to the strong penetration of the liquid into the pores of the substrate. The characteristics of the drug wetting/stability process may contribute to the development of their new forms, creating delivery systems with greater efficiency and lower side effects.
44

Song, Kui, Ruijie Huang, and Xiaoling Hu. "Imbibition of Newtonian Fluids in Paper-like Materials with the Infinitesimal Control Volume Method." Micromachines 12, no. 11 (November 12, 2021): 1391. http://dx.doi.org/10.3390/mi12111391.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Paper-based microfluidic devices are widely used in point-of-care testing applications. Imbibition study of paper porous media is important for fluid controlling, and then significant to the applications of paper-based microfluidic devices. Here we propose an analytical approach based on the infinitesimal control volume method to study the imbibition of Newtonian fluids in commonly used paper-like materials. Three common paper shapes (rectangular paper strips, fan-shaped and circular paper sheets) are investigated with three modeling methods (corresponding to equivalent tiny pores with circle, square and regular triangle cross section respectively). A model is derived for liquid imbibition in rectangular paper strips, and the control equations for liquid imbibition in fan-shaped and circular paper sheets are also derived. The model is verified by imbibition experiments done using the mixed cellulose ester filter paper and pure water. The relation of imbibition distance and time is similar to that of the Lucas−Washburn (L−W) model. In addition, a new porosity measurement method based on the imbibition in circular paper sheets is proposed and verified. Finally, the flow rates are investigated. This study can provide guidance for the design of different shapes of paper, and for better applications of paper-based microfluidic devices.
45

Yatsyshyn, S., and Kh Melnyk. "Inertia of liquid microthermometer readings." Metrology and instruments, no. 4 (September 7, 2019): 39–43. http://dx.doi.org/10.33955/2307-2180(4)2019.39-43.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Currently the need for micro thermometers with low inertia and accordingly with the small diameter of the capillary is increasing, and information about their inertia, which is necessary, in particular, for medicine, becomes insufficient. Micro thermometers with liquid-phase sensitive elements are made on the basis of capillaries filled with liquid. Important is the type of liquid (water, alcohol, mercury, etc.), the angle of inclination of the thermometer capillary, and its internal diameter. The time of their thermal inertia is rather small, since the thermal equilibrium of the thermometer and the controlled object is set extremely fast. However, in reality, the movement of a liquid in a capillary of a thermometer, which determines the readout of the temperature value, due to the change in the thermodynamic conditions during the measurement, is not so rapid to satisfy the metrology. The experience of studying the spontaneous penetration of liquids in porous micro and nano channels of natural structures is limited mainly by works that capture the significance of the influence of initial conditions. The features of filling capillaries of different internal diameters at different angles of inclination are considered in the paper. It enables us to work out the technology of manufacturing and application of these thermometers, and thus to predict the duration of setting the micro thermometers’ indications not limited by thermal inertia. For this purpose, the Washburn’s and Bosanquet equations are considered. Rate of filling the capillary is affected by fluid viscosity, surface tension, length of the filled capillary, and its diameter. Since the viscosity of the liquid increases slightly with pressure and decreases exponentially with temperature, it is inversely proportional to the rate of liquid penetration or to the rate of moving meniscus. We have analyzed the impact of these factors on the micro thermometers’ performance that promotes their efficient production and application.
46

Pereira, David Y., Chloe M. Wu, So Youn Lee, Eumene Lee, Benjamin M. Wu, and Daniel T. Kamei. "Controlling Macroscopic Phase Separation of Aqueous Two-Phase Polymer Systems in Porous Media." SLAS TECHNOLOGY: Translating Life Sciences Innovation 24, no. 5 (July 30, 2019): 515–26. http://dx.doi.org/10.1177/2472630319861369.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In previous work, our group discovered a phenomenon in which a mixed polymer–salt or mixed micellar aqueous two-phase system (ATPS) separates into its two constituent phases as it flows within paper. While these ATPSs worked well in their respective studies to concentrate the target biomarker and improve the sensitivity of the lateral-flow immunoassay, different ATPSs can be advantageous for new applications based on factors such as biomarker partitioning or biochemical compatibility between ATPS and sample components. However, since the mechanism of phase separation in porous media is not completely understood, introducing other ATPSs to paper is an unpredictable process that relies on trial and error experiments. This is especially true for polymer–polymer ATPSs in which the characteristics of the two phases appear quite similar. Therefore, our group aimed to develop semiquantitative guidelines for choosing ATPSs that can phase separate in paper. In this work, we evaluated the Washburn equation and its parameters as a potential mathematical framework to describe the flow behavior of polymer–salt and micellar ATPSs in fiberglass paper. We compared bulk phase fluid characteristics and identified the viscosity difference between the phases as a key determinant of the potential for phase separation in paper. We then used this parameter to predict the phase separation capabilities of polyethylene glycol (PEG)–dextran ATPSs in paper and control the composition of the leading and lagging phases. We also, for the first time, successfully demonstrated the phase separation phenomenon in hydrogels, thereby extending its application and potential benefits to an alternative porous medium.
47

Bautista, Oscar, Federico Méndez, and Eric Bautista. "Simultaneous Wicking-Convection Heat Transfer Process with Non-Newtonian Power-Law Fluid." Defect and Diffusion Forum 297-301 (April 2010): 117–25. http://dx.doi.org/10.4028/www.scientific.net/ddf.297-301.117.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
In this work, we have theoretically analyzed the heat convection process in a porous medium under the influence of spontaneous wicking of a non-Newtonian power-law fluid, trapped in a capillary element, considering the presence of a temperature gradient. The capillary element is represented by a porous medium which is initially found at temperature and pressure . Suddenly the lower part of the porous medium touches a reservoir with a non-Newtonian fluid with temperature and pressure . This contact between both phases, in turn causes spontaneously the wicking process. Using a one-dimensional formulation of the average conservation laws, we derive the corresponding nondimensional momentum and energy equations. The numerical solutions permit us to evaluate the position and velocity of the imbibitions front as well as the dimensionless temperature profiles and Nusselt number. The above results are shown by considering the physical influence of two nondimensional parameters: the ratio of the characteristic thermal time to the characteristic wicking time, , the ratio of the hydrostatic head of the imbibed fluid to the characteristic pressure difference between the wicking front and the dry zone of the porous medium, , and the power-law index, n, for the non-Newtonian fluid. The predictions show that the wicking and heat transfer process are strongly dependent on the above nondimensional parameters, indicating a clear deviation in comparison with and n = 1, that represents the classical Lucas-Washburn solution.
48

Dias, Madalena M., and Alkiviades C. Payatakes. "Network models for two-phase flow in porous media Part 2. Motion of oil ganglia." Journal of Fluid Mechanics 164 (March 1986): 337–58. http://dx.doi.org/10.1017/s0022112086002586.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
The behaviour of non-wetting ganglia undergoing immiscible displacement in a porous medium is studied with the help of a theoretical simulator. The porous medium is represented by a network of randomly sized unit cells of the constricted-tube type. The fluid of a non-wetting ganglion is in contact with the wetting fluid at menisci which are assumed to be spherical cups. The flow in every constricted unit cell occupied by a single fluid is modelled as flow in a sinusoidal tube. The flow in every unit cell that contains a meniscus and portions of both fluids is treated with a combination of a Washburn-type analysis and a lubrication-theory approximation. The flow problem is thus reduced to a system of linear equations the solution of which gives the instantaneous pressures on the nodes, the flowrates through the unit cells, and the velocities of the menisci. The motion of a ganglion is determined by assuming quasi-static flow, taking a small time increment, updating the positions of the menisci, and iterating. The behaviour of solitary ganglia is studied under conditions of quasi-static displacement (Ca slightly larger than critical), as well as dynamic displacement (Ca substantially larger than critical). Shape evolution, rate of flow, mode of break-up, and stranding are examined. The stranding and break-up coefficients are determined as functions of the capillary number and the ganglion size for a 100 × 200 sandpack. The dependence of the average ganglion velocity on ganglion size, capillary number, viscosity ratio and dynamic contact angle is examined for the simple case of motion between straight rows of spheres. It is found, among other things, that when μo < μw the velocity of ganglia can be substantially larger than that of the displacing fluid.
49

Koplik, J., and T. J. Lasseter. "Two-Phase Flow in Random Network Models of Porous Media." Society of Petroleum Engineers Journal 25, no. 01 (February 1, 1985): 89–100. http://dx.doi.org/10.2118/11014-pa.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Анотація:
Abstract To explore how the microscopic geometry of a pore space affects the macroscopic characteristics of fluid flow in porous media, we have used approximate solutions of the porous media, we have used approximate solutions of the Navier-Stokes equations to calculate the flow of two fluids in random networks. The model pore space consists of an array of pores of variable radius connected to a random number of nearest neighbors by throats of variable length and radius. The various size and connectedness distributions may be arbitrarily assigned, as are the wetting characteristics of the two fluids in the pore space. The fluids are assumed to be incompressible, immiscible. Newtonian, and of equal viscosity. In the calculation, we use Stokes flow results for the motion of the individual fluids and incorporate microscopic capillary force by using the Washburn approximation. At any time, the problem is mathematically identical to a random electrical network of resistors, batteries, and diodes. From the numerical solution of the latter, we compute the fluid velocities and saturation rates of change and use a discrete timestepping procedure to follow the subsequent motion. The scale of the computation has restricted us so far to networks of hundreds of pores in two dimensions (2D). Within these limitations, we discuss the dependence of residual oil saturations and interface shapes on network geometry and flow conditions. Introduction A significant limitation to our understanding of the dynamics of multiphase fluids in porous media is the inability to connect the physics at the microscopic scale to the macroscopic phenomena observed in the laboratory and in the field. Within individual pores, the motion of fluids and menisci can be discussed, at least approximately, in terms of the microgeometry and the physical characteristics of the liquids. gases, and solids present. On the macroscopic scale, the multiphase Darcy equations involving several empirical parameters-relative permeabilities and average capillary pressures permeabilities and average capillary pressures conventionally are used. The connection between these two levels of description, if there is one, has never been elucidated despite years of effort (as reviewed by Scheidegger ). In consequence, it is difficult to predict the behavior of oil reservoirs in advance, and considerable waste of money, effort, and resources can ensue. Economic issues aside, this situation provides another example of a pervasive problem in physics: macroscopic averaging of a random problem in physics: macroscopic averaging of a random microscopically disordered medium to predict large-scale behavior from a knowledge of small-scale dynamics. In optimal circumstances, existing methods in the physics literature (i.e., Ziman ) can be used to carry out physics literature (i.e., Ziman ) can be used to carry out the averaging. For fluid problems, for example, percolation theory has been applied to the spatial distribution of percolation theory has been applied to the spatial distribution of fluids in a pore space, both in static situations and in quasistatic displacement. Another set of ideas, effective medium theories, has been applied to electrical conductivity and its fluid analog, absolute permeability. The general fluid displacement problem, when both permeability. The general fluid displacement problem, when both capillary and viscous forces are present, is related to a class of physics problems that are as yet unresolved, such as crystal growth, surface evolution, and dynamic percolation. In this situation, we are forced to resort to percolation. In this situation, we are forced to resort to brute-force numerical modeling, both as a means of obtaining statistical information and as a guide to approximations that may permit future analytical work. In this paper, we describe our initial efforts to calculate the motion of two fluids in porous media from the microscopic scale up, starting from the Stokes equations and boundary conditions in this pore space. As usual, we model the porous medium as a network of similarly shaped, but randomly sized, elements. The key to the calculation is the mathematical analogy between the fluid problem and an appropriate electrical network of random problem and an appropriate electrical network of random resistors, batteries, and diodes. The calculation is a very difficult one, numerically speaking, and to date we have been restricted to fairly small 2D networks of hundreds of pores. We expect, however, that with more sophisticated programming methods our approach can be applied to three-dimensional (3D) networks of thousands of pores. pores. After this work was in progress, we came across a paper of Singhal and Somerton where a similar calculational framework was used but with a different emphasis. Those authors considered a single realization of a small network of triangular channels of random sizes with flow regimes randomly assigned in each channel and compute the relative permeabilities and capillary pressure curves of the network. Our emphasis in this paper is on time-dependent phenomena and statistical averaging of flow quantities. We also note the somewhat related work by Payatakes et al., who considered a square lattice of Payatakes et al., who considered a square lattice of converging/diverging tubes meeting at point nodes and simulate the dislodgement of blobs of trapped oil. Subsequently, Dias and Payatakes used the same geometry and calculational rules similar to those employed here to study fluid displacement. SPEJ P. 89
50

Dimitrov, D. I., A. Milchev, and K. Binder. "Capillary Rise in Nanopores: Molecular Dynamics Evidence for the Lucas-Washburn Equation." Physical Review Letters 99, no. 5 (July 31, 2007). http://dx.doi.org/10.1103/physrevlett.99.054501.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

До бібліографії