A Many-Body Dissipative Particle Dynamics Study of Spontaneous Capillary Imbibition and Drainage

详细信息    查看全文

• 作者：Chen Chen ; Chunning Gao ; Lin Zhuang ; Xuefeng Li ; Pingcang Wu ; Jinfeng Dong ; Juntao Lu
• 刊名：Langmuir
• 出版年：2010
• 出版时间：June 15, 2010
• 年：2010
• 卷：26
• 期：12
• 页码：9533-9538
• 全文大小：886K
• 年卷期：v.26,no.12(June 15, 2010)
• ISSN：1520-5827

文摘

The spontaneous capillary imbibition and drainage processes are studied using many-body dissipative particle dynamics (MDPD) simulations. By adjusting the solid−liquid interaction parameter, different wetting behavior between the fluid and the capillary wall, corresponding to the static contact angle ranging from 0° to 180°, can be controllably simulated. For wetting fluids, the spontaneous capillary imbibition (SCI) is evident in MDPD simulations. It is found that, whereas the corrected Lucas−Washburn equation (taking into account the dynamic contact angle and the fluid inertia) can well describe the SCI simulation result for the completely wetting fluid, it deviates, to a notable degree, from the results of partly wetting fluids. In particular, this corrected equation cannot be used to describe the spontaneous capillary drainage (SCD) processes. To solve this problem, we derive an improved form of the Lucas−Washburn equation, in which the slip effects of fluid particles at the capillary wall are treated. Such an improved equation turns out to be capable of describing all the simulation results of both the SCI and the SCD. These findings provide new insights into the SCI and SCD processes and improve the mathematical base.