A model of spontaneous flow driven by capillary pressure in nanoporous media

Shen, Anqi; Liu, Yikun; Ali, S.M. Farouq

doi:10.26804/capi.2020.01.01

Cited by 20 publications

(4 citation statements)

References 29 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Schebarchov and Hendy modified the LW equation considering a Navier slip length b at the nanoscale as follows Apart from considering slippage, inherent wall roughness and effective viscosity are also taken into account separately to accurately characterize the capillary imbibition behavior in nanopores based on the LW equation. The capillary imbibition model considering effective viscosity and slippage in nanopores can therefore be expressed as follows where c is the constant for water.…”

Section: Modifications and Extensions Of The Lw Equationmentioning

confidence: 99%

Lucas–Washburn Equation-Based Modeling of Capillary-Driven Flow in Porous Systems

et al. 2021

View full text Add to dashboard Cite

Fluid flow in porous systems driven by capillary pressure is one of the most ubiquitous phenomena in nature and industry, including petroleum and hydraulic engineering as well as material and life sciences. The classical Lucas–Washburn (LW) equation and its modified forms were developed and have been applied extensively to elucidate the fundamental mechanisms underlying the basic statics and dynamics of the capillary-driven flow in porous systems. The LW equation assumes that fluids are incompressible Newton ones and that capillary channels all have the same radii. This kind of hypothesis is not true for many natural situations, however, where porous systems comprise complicated pore and capillary channel structures at microscales. The LW equation therefore often leads to inaccurate capillary imbibition predictions in such situations. Numerous studies have been conducted in recent years to develop and assess the modifications and extensions of the LW equation in various porous systems. Significant progresses in computational techniques have also been attained to further improve our understanding of imbibition dynamics. A state-of-the-art review is therefore needed to summarize the recent significant models and numerical simulation techniques as well as to discuss key ongoing research topics arising from various new engineering practices. The theoretical basis of the LW equation is first introduced in this review and recent progress in mathematical models is then summarized to demonstrate the modifications and extensions of this equation to various microchannels and porous media. These include capillary tubes with nonuniform and noncircular cross sections, discrete fractures, and capillary tubes that are not straight as well as heterogeneous porous media. Numerical studies on the LW equation are also reviewed, and comments on future works and research directions for LW-based capillary-driven flows in porous systems are listed.

show abstract

Section: Modifications and Extensions Of The Lw Equationmentioning

confidence: 99%

Lucas–Washburn Equation-Based Modeling of Capillary-Driven Flow in Porous Systems

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In essence, capillary pressure is the pressure difference between vapor-phase pressure and liquid-phase pressure, which is inversely proportional to pore size. As a result, capillary pressure cannot be neglected at the nanoscale, which turns out to be relatively good at dramatically varying vapor-phase density and liquid-phase density [47,48], further affecting phase behavior. Notably, when compared with the conventional formula for capillary pressure, Formula (11) (designed for nanoconfined capillary pressure) takes into account the adsorption-phase thickness.…”

Section: Capillary Pressurementioning

confidence: 99%

The Influence of Wettability Effect and Adsorption Thickness on Nanoconfined Methane Phase Behavior: Vapor-Liquid Co-Existence Curves and Phase Diagrams

Wu,

Zeng,

Cheng

et al. 2024

Processes

View full text Add to dashboard Cite

Research interest in the behavior of methane inside nanopores has been growing, driven by the substantial geological reserves of shale gas and coalbed methane. The phase diagram of methane in nanopores differs significantly from its bulk state, influencing its existing form and pertinent physical properties—such as density and viscosity—at specific pressures and temperatures. Currently, there is a lack of effort to understand the nanoconfinement effect on the methane phase diagram; this is a crucial issue that needs urgent attention before delving into other aspects of nanoconfined methane behavior. In this study, we establish a fully coupled model to predict the methane phase diagram across various scales. The model is based on vapor-liquid fugacity equilibrium, considering the shift in critical pressure and temperature induced by pore size shrinkage and adsorption-phase thickness. Notably, our proposed model incorporates the often-overlooked factor of capillary pressure, which is greatly amplified by nanoscale pore size and the presence of the adsorption phase. Additionally, we investigated the impact of surface wettability, correlated to capillary pressure and the shift in critical properties, on the methane phase diagram. Our results indicate that (a) as pore size decreases, the methane phase diagram becomes more vertical, suggesting a transition from a gaseous to a liquid state for some methane molecules, which is contrary to the conventional phase diagram; (b) enhancing surface wettability results in a more vertical phase diagram, with the minimum temperature corresponding to 0 MPa pressure on the phase diagram, increasing by as much as 87.3%; (c) the influence of capillary pressure on the phase diagram is more pronounced under strong wettability conditions compared to weak wettability, and the impact from the shift in critical properties can be neglected when the pore size exceeds 50 nm.

show abstract

“…Han et al experimentally investigated the infiltration of glycerin in a lyophobic nanoporous silica gel and found that the effective liquid viscosity is highly dependent on the pore size and the loading rate. Shen et al conducted experiments on the pressure-driven infiltration of deionized water into nanopores. The results demonstrate that spontaneous absorption in nanoporous media can be scaled and predicted.…”

Section: Introductionmentioning

confidence: 99%

Study on the Influence of Loading Rate on the Cascade Characteristics of Nanofluidic Systems

Zhang,

Liu,

Xiao

et al. 2024

Energy Fuels

View full text Add to dashboard Cite

The energy absorption density of the nanofluidic energy absorption system (NEAS) is much higher than that of traditional energy-absorbing materials. An NEAS based on different pore size combinations may exhibit cascade characteristics, which can achieve energy absorption of different grades. In this work, two NEAS models based on carbon nanotubes are constructed, which are DNEAS and SNEAS. In DNEAS, two tubes with both ends immersed in a water reservoir are used. In SNEAS, two tubes are connected end to end, with the end of the bigger tube immersed in the water reservoir. The effects of loading rate coupled to pore size on the infiltration processes of water molecules into two models were investigated. The fitting correlations between the critical pore size difference and temperature were established. It has been observed that an increase in loading rate will transform a single-stage system into a multistage system that displays cascade characteristics. The critical pore size difference for the system to display cascade characteristics decreases with an increase in the loading rate. In DNEAS, the infiltration processes of the large and small tubes are independent of each other, and the effect of the loading rate on energy absorption characteristics is the superposition of that of the corresponding single tube NEAS. In SNEAS, the water molecules fill up the bottom tube before infiltrating the top tube. The influence of the effective viscosity change caused by loading rate on infiltration pressure is greater than that of hydrogen bond loss during the entry of water molecules into the bottom tube. The critical infiltration pressure as well as the total energy absorption of the top tube in SNEAS were higher than that of the corresponding single tube NEAS. The research findings have expanded the fundamental database of cascade nanofluidic systems and offer valuable insights for the application design of such systems.

show abstract

A model of spontaneous flow driven by capillary pressure in nanoporous media

Cited by 20 publications

References 29 publications

Lucas–Washburn Equation-Based Modeling of Capillary-Driven Flow in Porous Systems

Lucas–Washburn Equation-Based Modeling of Capillary-Driven Flow in Porous Systems

The Influence of Wettability Effect and Adsorption Thickness on Nanoconfined Methane Phase Behavior: Vapor-Liquid Co-Existence Curves and Phase Diagrams

Study on the Influence of Loading Rate on the Cascade Characteristics of Nanofluidic Systems

Contact Info

Product

Resources

About