Work

Capillary filling dynamics in polygonal tubes

Year: 2025

Type: article

Abstract: We study the dynamics of capillary filling in tubes of regular polygon cross section. Using the Onsager variational principle, we derive a coupled ordinary differential equation and a partial differential equation, which respectively describe time evolution of the bulk flow and the saturation profile of the finger flow. We obtain both numerical solution and self-similar solution to the coupled equations, and the results indicate that the bulk flow and the finger flow both follow the t1/2 time scaling. We show that due to the coupling effect of the finger flow, the prefactor for the bulk flow is smaller than that of the Lucas-Washburn prediction. The reduction effect is more pronounced when the side number n of the regular-polygon is small, while as n increases, the prefactor approaches Lucas-Washburn prediction.

Source: Physics of Fluids

DOI: 10.1063/5.0260670

Authors: Chen Zhao, Yu Huang, Tingxuan Chen, Jiaxuan Li, Jiajia Zhou, Masao Doi

Institutions: Chinese Academy of Sciences, Institute of Theoretical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, South China University of Technology

Language: English

Topic: Fluid Dynamics and Heat Transfer

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: National Natural Science Foundation of China, National Key Research and Development Program of China

Awards: G3628066574, G6742165379